Fix linting errors in README page

Fix the issues that will prevent this page from moving into the
regular docs directory. Also, add metadata for the Source Code group.

workhorse/README.md

+---
+stage: Create
+group: Source Code
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+---
+
 # GitLab Workhorse
 
 GitLab Workhorse is a smart reverse proxy for GitLab. It handles
@@ -10,26 +16,25 @@ GitLab](doc/architecture/gitlab_features.md) that would not work efficiently wit
 ## Canonical source
 
 The canonical source for Workhorse is
-[gitlab-org/gitlab/workhorse](https://gitlab.com/gitlab-org/gitlab/tree/master/workhorse).
-Prior to https://gitlab.com/groups/gitlab-org/-/epics/4826, it was
-[gitlab-org/gitlab-workhorse](https://gitlab.com/gitlab-org/gitlab-workhorse/tree/master),
+[`gitlab-org/gitlab/workhorse`](https://gitlab.com/gitlab-org/gitlab/tree/master/workhorse).
+Prior to [epic #4826](https://gitlab.com/groups/gitlab-org/-/epics/4826), it was
+[`gitlab-org/gitlab-workhorse`](https://gitlab.com/gitlab-org/gitlab-workhorse/tree/master),
 but that repository is no longer used for development.
 
 ## Documentation
 
 Workhorse documentation is available in the [`doc` folder of this repository](doc/).
 
-* Architectural overview
-  * [GitLab features that rely on Workhorse](doc/architecture/gitlab_features.md)
-  * [Websocket channel support](doc/architecture/channel.md)
-* Operating Workhorse
-  * [Source installation](doc/operations/install.md)
-  * [Workhorse configuration](doc/operations/configuration.md)
-* [Contributing](CONTRIBUTING.md)
-  * [Adding new features](doc/development/new_features.md)
-  * [Testing your code](doc/development/tests.md)
+- Architectural overview
+  - [GitLab features that rely on Workhorse](doc/architecture/gitlab_features.md)
+  - [Websocket channel support](doc/architecture/channel.md)
+- Operating Workhorse
+  - [Source installation](doc/operations/install.md)
+  - [Workhorse configuration](doc/operations/configuration.md)
+- [Contributing](CONTRIBUTING.md)
+  - [Adding new features](doc/development/new_features.md)
+  - [Testing your code](doc/development/tests.md)
 
 ## License
 
 This code is distributed under the MIT license, see the [LICENSE](LICENSE) file.
-

workhorse/doc/architecture/channel.md

+---
+stage: Create
+group: Source Code
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+---
+
 # Websocket channel support
 
 In some cases, GitLab can provide in-browser terminal access to an
@@ -22,7 +28,7 @@ responses. WebSocket URLs have schemes like `ws://` (unencrypted) or
 When requesting an upgrade to WebSocket, the browser sends a HTTP/1.1
 request that looks like this:
 
-```
+```plaintext
 GET /path.ws HTTP/1.1
 Connection: upgrade
 Upgrade: websocket
@@ -116,10 +122,10 @@ This returns a JSON response containing details of where the
 terminal can be found, and how to connect it. In particular,
 the following details are returned in case of success:
 
-* WebSocket URL to **connect** to, e.g.: `wss://example.com/terminals/1.ws?tty=1`
-* WebSocket subprotocols to support, e.g.: `["channel.k8s.io"]`
-* Headers to send, e.g.: `Authorization: Token xxyyz..`
-* Certificate authority to verify `wss` connections with (optional)
+- WebSocket URL to **connect** to, e.g.: `wss://example.com/terminals/1.ws?tty=1`
+- WebSocket subprotocols to support, e.g.: `["channel.k8s.io"]`
+- Headers to send, e.g.: `Authorization: Token xxyyz..`
+- Certificate authority to verify `wss` connections with (optional)
 
 Workhorse periodically re-checks this endpoint, and if it gets an
 error response, or the details of the terminal change, it will
@@ -186,9 +192,8 @@ written to that fd.
 Also used by Kubernetes, this subprotocol defines a similar multiplexed
 channel to `channel.k8s.io`. The main differences are:
 
-* `TextMessage` frames are valid, rather than `BinaryMessage` frames.
-* The first byte of each `TextMessage` frame represents the file
+- `TextMessage` frames are valid, rather than `BinaryMessage` frames.
+- The first byte of each `TextMessage` frame represents the file
   descriptor as a numeric UTF-8 character, so the character `U+0030`,
   or "0", is fd 0, STDIN).
-* The remaining bytes represent base64-encoded arbitrary data.
-
+- The remaining bytes represent base64-encoded arbitrary data.

workhorse/doc/architecture/gitlab_features.md

+---
+stage: Create
+group: Source Code
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+---
+
 # Features that rely on Workhorse
 
 Workhorse itself is not a feature, but there are several features in
 GitLab that would not work efficiently without Workhorse.
 
 To put the efficiency benefit in context, consider that in 2020Q3 on
-GitLab.com [we see][thanos] Rails application threads using on average
+GitLab.com [we see][https://thanos-query.ops.gitlab.net/graph?g0.range_input=1h&g0.max_source_resolution=0s&g0.expr=sum(ruby_process_resident_memory_bytes%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)%20%2F%20sum(puma_max_threads%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)&g0.tab=1&g1.range_input=1h&g1.max_source_resolution=0s&g1.expr=sum(go_memstats_sys_bytes%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)%2Fsum(go_goroutines%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)&g1.tab=1]
+Rails application threads using on average
 about 200MB of RSS vs about 200KB for Workhorse goroutines.
 
 Examples of features that rely on Workhorse:
@@ -63,7 +70,4 @@ memory than it costs to have Workhorse look after it.
 - Workhorse does not clean up idle client connections.
 - We assume that all requests to Rails pass through Workhorse.
 
-For more information see ['A brief history of GitLab Workhorse'][brief-history-blog].
-
-[thanos]: https://thanos-query.ops.gitlab.net/graph?g0.range_input=1h&g0.max_source_resolution=0s&g0.expr=sum(ruby_process_resident_memory_bytes%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)%20%2F%20sum(puma_max_threads%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)&g0.tab=1&g1.range_input=1h&g1.max_source_resolution=0s&g1.expr=sum(go_memstats_sys_bytes%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)%2Fsum(go_goroutines%7Bapp%3D%22webservice%22%2Cenv%3D%22gprd%22%2Crelease%3D%22gitlab%22%7D)&g1.tab=1
-[brief-history-blog]: https://about.gitlab.com/2016/04/12/a-brief-history-of-gitlab-workhorse/
+For more information see ['A brief history of GitLab Workhorse'](https://about.gitlab.com/2016/04/12/a-brief-history-of-gitlab-workhorse/).

workhorse/doc/development/new_features.md

-## Adding new features to Workhorse
+---
+stage: Create
+group: Source Code
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+---
+
+# Adding new features to Workhorse
 
 GitLab Workhorse is a smart reverse proxy for GitLab. It handles
 "long" HTTP requests such as file downloads, file uploads, Git
@@ -16,14 +22,14 @@ We suggest to follow this route only if absolutely necessary and no other option
 
 Splitting a feature between the Rails code-base and Workhorse is deliberately choosing to introduce technical debt. It adds complexity to the system and coupling between the two components.
 
-* Building features using Workhorse has a considerable complexity cost, so you should prefer designs based on Rails requests and Sidekiq jobs.
-* Even when using Rails+Sidekiq is "more work" than using Rails+Workhorse, Rails+Sidekiq is easier to maintain in the long term because Workhorse is unique to GitLab while Rails+Sidekiq is an industry standard.
-* For "global" behaviors around web requests consider using a Rack middleware instead of Workhorse.
-* Generally speaking, we should only use Rails+Workhorse if the HTTP client expects behavior that is not reasonable to implement in Rails, like "long" requests.
+- Building features using Workhorse has a considerable complexity cost, so you should prefer designs based on Rails requests and Sidekiq jobs.
+- Even when using Rails+Sidekiq is "more work" than using Rails+Workhorse, Rails+Sidekiq is easier to maintain in the long term because Workhorse is unique to GitLab while Rails+Sidekiq is an industry standard.
+- For "global" behaviors around web requests consider using a Rack middleware instead of Workhorse.
+- Generally speaking, we should only use Rails+Workhorse if the HTTP client expects behavior that is not reasonable to implement in Rails, like "long" requests.
 
 ## What is a "long" request?
 
-There is one order of magnitude between Workhorse and puma RAM usage. Having connection open for a period longer than milliseconds is a problem because of the amount of RAM it monopolizes once it reaches the Ruby on Rails controller.
+There is one order of magnitude between Workhorse and Puma RAM usage. Having connection open for a period longer than milliseconds is a problem because of the amount of RAM it monopolizes once it reaches the Ruby on Rails controller.
 
 So far we identified two classes of "long" requests: data transfers and HTTP long polling.
 
@@ -37,5 +43,4 @@ You can watch the recording for more details on the history of Workhorse and the
 [Uploads development documentation]( https://docs.gitlab.com/ee/development/uploads.html)
 contains the most common use-cases for adding a new type of upload and may answer all of your questions.
 
-If you still think we should add a new feature to Workhorse, please open an issue explaining **what you want to implement** and **why it can't be implemented in our ruby code-base**. Workhorse maintainers will be happy to help you assessing the situation.
-
+If you still think we should add a new feature to Workhorse, please open an issue explaining **what you want to implement** and **why it can't be implemented in our Ruby code-base**. Workhorse maintainers will be happy to help you assessing the situation.

workhorse/doc/development/tests.md

+---
+stage: Create
+group: Source Code
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+---
+
 # Testing your code
 
 Run the tests with:
 
-```
+```plaintext
 make clean test
 ```
 

workhorse/doc/operations/configuration.md

+---
+stage: Create
+group: Source Code
+info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://about.gitlab.com/handbook/engineering/ux/technical-writing/#assignments
+---
+
 # Workhorse configuration
 
 For historical reasons Workhorse uses both command line flags, a configuration file and environment variables.
@@ -6,7 +12,7 @@ All new configuration options that get added to Workhorse should go into the con
 
 ## CLI options
 
-```
+```plaintext
   gitlab-workhorse [OPTIONS]
 
 Options:
@@ -60,10 +66,10 @@ HTTP.
 
 GitLab Workhorse can listen on either a TCP or a Unix domain socket. It
 can also open a second listening TCP listening socket with the Go
-[net/http/pprof profiler server](http://golang.org/pkg/net/http/pprof/).
+[`net/http/pprof` profiler server](http://golang.org/pkg/net/http/pprof/).
 
-GitLab Workhorse can listen on redis events (currently only builds/register
-for runners). This requires you to pass a valid TOML config file via
+GitLab Workhorse can listen on Redis events (currently only builds/register
+for runners). This requires you to pass a valid TOML configuration file via
 `-config` flag.
 For regular setups it only requires the following (replacing the string
 with the actual socket)
@@ -73,19 +79,19 @@ with the actual socket)
 GitLab Workhorse integrates with Redis to do long polling for CI build
 requests. This is configured via two things:
 
--   Redis settings in the TOML config file
--   The `-apiCiLongPollingDuration` command line flag to control polling
-    behavior for CI build requests
+- Redis settings in the TOML configuration file
+- The `-apiCiLongPollingDuration` command line flag to control polling
+  behavior for CI build requests
 
-It is OK to enable Redis in the config file but to leave CI polling
+It is OK to enable Redis in the configuration file but to leave CI polling
 disabled; this just results in an idle Redis pubsub connection. The
 opposite is not possible: CI long polling requires a correct Redis
 configuration.
 
-Below we discuss the options for the `[redis]` section in the config
+Below we discuss the options for the `[redis]` section in the configuration
 file.
 
-```
+```plaintext
 [redis]
 URL = "unix:///var/run/gitlab/redis.sock"
 Password = "my_awesome_password"
@@ -95,12 +101,15 @@ SentinelMaster = "mymaster"
 
 - `URL` takes a string in the format `unix://path/to/redis.sock` or
 `tcp://host:port`.
-- `Password` is only required if your redis instance is password-protected
+- `Password` is only required if your Redis instance is password-protected
 - `Sentinel` is used if you are using Sentinel.
-  *NOTE* that if both `Sentinel` and `URL` are given, only `Sentinel` will be used
+
+  NOTE:
+  If both `Sentinel` and `URL` are given, only `Sentinel` will be used.
 
 Optional fields are as follows:
-```
+
+```plaintext
 [redis]
 DB = 0
 MaxIdle = 1
@@ -108,7 +117,7 @@ MaxActive = 1
 ```
 
 - `DB` is the Database to connect to. Defaults to `0`
-- `MaxIdle` is how many idle connections can be in the redis-pool at once. Defaults to 1
+- `MaxIdle` is how many idle connections can be in the Redis pool at once. Defaults to 1
 - `MaxActive` is how many connections the pool can keep. Defaults to 1
 
 ## Relative URL support
@@ -117,7 +126,7 @@ If you are mounting GitLab at a relative URL, e.g.
 `example.com/gitlab`, then you should also use this relative URL in
 the `authBackend` setting:
 
-```
+```plaintext
 gitlab-workhorse -authBackend http://localhost:8080/gitlab
 ```
 
@@ -151,7 +160,7 @@ development.
 
 Omnibus (`/etc/gitlab/gitlab.rb`):
 
-```
+```ruby
 gitlab_workhorse['env'] = {
     'GITLAB_WORKHORSE_SENTRY_DSN' => 'https://foobar'
     'GITLAB_WORKHORSE_SENTRY_ENVIRONMENT' => 'production'
@@ -160,16 +169,16 @@ gitlab_workhorse['env'] = {
 
 Source installations (`/etc/default/gitlab`):
 
-```
+```plaintext
 export GITLAB_WORKHORSE_SENTRY_DSN='https://foobar'
 export GITLAB_WORKHORSE_SENTRY_ENVIRONMENT='production'
 ```
 
 ## Distributed Tracing
 
-Workhorse supports distributed tracing through [LabKit][] using [OpenTracing APIs](https://opentracing.io).
+Workhorse supports distributed tracing through [LabKit](https://gitlab.com/gitlab-org/labkit/) using [OpenTracing APIs](https://opentracing.io).
 
-By default, no tracing implementation is linked into the binary, but different OpenTracing providers can be linked in using [build tags][build-tags]/[build constraints][build-tags]. This can be done by setting the `BUILD_TAGS` make variable.
+By default, no tracing implementation is linked into the binary, but different OpenTracing providers can be linked in using [build tags](https://golang.org/pkg/go/build/#hdr-Build_Constraints) or build constraints. This can be done by setting the `BUILD_TAGS` make variable.
 
 For more details of the supported providers, see LabKit, but as an example, for Jaeger tracing support, include the tags: `BUILD_TAGS="tracer_static tracer_static_jaeger"`.
 
@@ -187,9 +196,9 @@ GITLAB_TRACING=opentracing://jaeger ./gitlab-workhorse
 
 ## Continuous Profiling
 
-Workhorse supports continuous profiling through [LabKit][] using [Stackdriver Profiler](https://cloud.google.com/profiler).
+Workhorse supports continuous profiling through [LabKit](https://gitlab.com/gitlab-org/labkit/) using [Stackdriver Profiler](https://cloud.google.com/profiler).
 
-By default, the Stackdriver Profiler implementation is linked in the binary using [build tags][build-tags], though it's not
+By default, the Stackdriver Profiler implementation is linked in the binary using [build tags](https://golang.org/pkg/go/build/#hdr-Build_Constraints), though it's not
 required and can be skipped.
 
 For example:
@@ -207,7 +216,4 @@ For example:
 GITLAB_CONTINUOUS_PROFILING="stackdriver?service=workhorse&service_version=1.0.1&project_id=test-123 ./gitlab-workhorse"
 ```
 
-More information about see the [LabKit monitoring docs](https://gitlab.com/gitlab-org/labkit/-/blob/master/monitoring/doc.go).
-
-[LabKit]: https://gitlab.com/gitlab-org/labkit/
-[build-tags]: https://golang.org/pkg/go/build/#hdr-Build_Constraints
+More information about see the [LabKit monitoring documentation](https://gitlab.com/gitlab-org/labkit/-/blob/master/monitoring/doc.go).

workhorse/doc/operations/install.md

@@ -6,13 +6,13 @@ Make](https://www.gnu.org/software/make/).
 
 To install into `/usr/local/bin` run `make install`.
 
-```
+```plaintext
 make install
 ```
 
 To install into `/foo/bin` set the PREFIX variable.
 
-```
+```plaintext
 make install PREFIX=/foo
 ```
 
@@ -26,19 +26,19 @@ On some operating systems, such as FreeBSD, you may have to use
 
 ### Exiftool
 
-Workhorse uses [exiftool](https://www.sno.phy.queensu.ca/~phil/exiftool/) for
+Workhorse uses [Exiftool](https://www.sno.phy.queensu.ca/~phil/exiftool/) for
 removing EXIF data (which may contain sensitive information) from uploaded
 images. If you installed GitLab:
 
--   Using the Omnibus package, you're all set.
-    *NOTE* that if you are using CentOS Minimal, you may need to install `perl`
-    package: `yum install perl`
--   From source, make sure `exiftool` is installed:
+- Using the Omnibus package, you're all set.
+  *NOTE* that if you are using CentOS Minimal, you may need to install `perl`
+  package: `yum install perl`
+- From source, make sure `exiftool` is installed:
 
-    ```sh
-    # Debian/Ubuntu
-    sudo apt-get install libimage-exiftool-perl
+  ```shell
+  # Debian/Ubuntu
+  sudo apt-get install libimage-exiftool-perl
 
-    # RHEL/CentOS
-    sudo yum install perl-Image-ExifTool
-    ```
+  # RHEL/CentOS
+  sudo yum install perl-Image-ExifTool
+  ```