Docs: Removed page metadata from the style guide

doc/development/documentation/index.md

@@ -105,22 +105,22 @@ info: To determine the technical writer assigned to the Stage/Group associated w
 ---
 ```
 
-### Page type metadata
+### Document type metadata
 
 Originally discussed in [this epic](https://gitlab.com/groups/gitlab-org/-/epics/1280),
-each page should have a `type` metadata. It can be one or more of the following:
-
-- `index`: Index/overview pages. They serve as a list to other pages. Doesn't
-  necessarily mean the page should be named `index.md`. [Example page](../../install/README.md).
-- `concepts`: What you need to know before using product. Informational, not
-  instructional. For example, abstract ideas, explain meaning or benefit, support
-  understanding of tasks. They are read for background information, for example
-  "Why X is important". [Example page](../../topics/autodevops/index.md).
-- `howto`: Specific use case instructions. [Example page](../../ssh/README.md).
-- `tutorial`: Learn a process/concept by doing. [Example page](../../gitlab-basics/start-using-git.md).
-- `reference`: Covers what things are/do. Things like specific settings, facts
-  without too much explanation that are read for detailed information.
-  [Example page](../../ci/yaml/README.md).
+each page should have a metadata tag called `type`. It can be one or more of the
+following:
+
+- `index`: It consists mostly of a list of links to other pages.
+  [Example page](../../README.md).
+- `concepts`: The background or context of a subject.
+  [Example page](../../topics/autodevops/index.md).
+- `howto`: Specific use case instructions.
+  [Example page](../../ssh/README.md).
+- `tutorial`: Learn a process/concept by doing.
+  [Example page](../../gitlab-basics/start-using-git.md).
+- `reference`: A collection of information used as a reference to use a feature
+  or a functionality. [Example page](../../ci/yaml/README.md).
 
 ### Redirection metadata
 
@@ -147,17 +147,10 @@ comments: false
 
 ### Additional page metadata
 
-Each page can have additional (optional) metadata (set in the
+Each page can have additional, optional metadata (set in the
 [default.html](https://gitlab.com/gitlab-org/gitlab-docs/-/blob/fc3577921343173d589dfa43d837b4307e4e620f/layouts/default.html#L30-52)
-Nanoc layout), which will be shown to the top of the page if defined:
-
-- `author`: The name of the author of a page, usually a tutorial. It requires `author_gitlab` in order to be shown.
-- `author_gitlab`: The username of the author on GitLab.com. It requires `author` in order to be shown.
-- `date`: The date the page was created, usually for tutorials.
-- `article_type`: The type of article. Can be either `tutorial` or `user guide`.
-- `level`: The level of complexity of a how-to or tutorial. Can be either `beginner`,
-  `advanced`, or `intermediate`.
-- `last_updated`: The date in ISO format when the page was last updated. For example `2020-02-14`.
+Nanoc layout), which will be displayed at the top of the page if defined:
+
 - `reading_time`: If you want to add an indication of the approximate reading
   time of a page, you can set `reading_time` to `true`. This uses a simple
   [algorithm](https://gitlab.com/gitlab-org/gitlab-docs/-/blob/master/lib/helpers/reading_time.rb)