Update CI/CD index and get started pages

doc/ci/index.md

@@ -9,33 +9,23 @@ type: index
 
 # GitLab CI/CD **(FREE)**
 
-GitLab CI/CD is a tool built into GitLab for software development
-through the [continuous methodologies](introduction/index.md):
+GitLab CI/CD is a tool for software development using the continuous methodologies:
 
-- Continuous Integration (CI)
-- Continuous Delivery (CD)
-- Continuous Deployment (CD)
+- [Continuous Integration (CI)](introduction/index.md#continuous-integration)
+- [Continuous Delivery (CD)](introduction/index.md#continuous-delivery)
+- [Continuous Deployment (CD)](introduction/index.md#continuous-deployment)
 
 NOTE:
 Out-of-the-box management systems can decrease hours spent on maintaining toolchains by 10% or more.
 Watch our ["Mastering continuous software development"](https://about.gitlab.com/webcast/mastering-ci-cd/)
-webcast to learn about continuous methods and how the GitLab built-in CI can help you simplify and scale software development.
+webcast to learn about continuous methods and how GitLab CI/CD can help you simplify and scale software development.
 
-Continuous Integration works by pushing small code chunks to your
-application's codebase hosted in a Git repository, and to every
-push, run a pipeline of scripts to build, test, and validate the
-code changes before merging them into the main branch.
-
-Continuous Delivery and Deployment consist of a step further CI,
-deploying your application to production at every
-push to the default branch of the repository.
-
-These methodologies allow you to catch bugs and errors early in
-the development cycle, ensuring that all the code deployed to
+Use GitLab CI/CD to catch bugs and errors early in
+the development cycle. Ensure that all the code deployed to
 production complies with the code standards you established for
 your app.
 
-GitLab can also automatically detect, build, test, deploy, and
+GitLab CI/CD can automatically build, test, deploy, and
 monitor your applications by using [Auto DevOps](../topics/autodevops/index.md).
 
 For a complete overview of these methodologies and GitLab CI/CD,
@@ -82,10 +72,9 @@ GitLab CI/CD supports numerous configuration options:
 Certain operations can only be performed according to the
 [user](../user/permissions.md#gitlab-cicd-permissions) and [job](../user/permissions.md#job-permissions) permissions.
 
-## Feature set
+## Features
 
-Use the vast GitLab CI/CD to easily configure it for specific purposes.
-Its feature set is listed on the table below according to DevOps stages.
+GitLab CI/CD features, grouped by DevOps stage, include:
 
 | Feature                                                                                         | Description                                                                                                                    |
 |:------------------------------------------------------------------------------------------------|:-------------------------------------------------------------------------------------------------------------------------------|
@@ -122,28 +111,27 @@ Its feature set is listed on the table below according to DevOps stages.
 
 ## Examples
 
-Find example project code and tutorials for using GitLab CI/CD with a variety of app frameworks, languages, and platforms
-on the [CI Examples](examples/README.md) page.
+See the [CI/CD examples](examples/README.md) page for example project code and tutorials for
+using GitLab CI/CD with various:
 
-## Administration **(FREE SELF)**
+- App frameworks
+- Languages
+- Platforms
 
-As a GitLab administrator, you can change the default behavior
-of GitLab CI/CD for:
+## Administration
 
-- An [entire GitLab instance](../user/admin_area/settings/continuous_integration.md).
-- Specific projects, using [pipelines settings](pipelines/settings.md).
+You can change the default behavior of GitLab CI/CD for:
+
+- An entire GitLab instance in the [CI/CD administration settings](../administration/index.md#cicd-settings).
+- Specific projects in the [pipelines settings](pipelines/settings.md).
 
 See also:
 
 - [Enable or disable GitLab CI/CD in a project](enable_or_disable_ci.md).
-- [Disable GitLab CI/CD by default in new projects](../administration/cicd.md). **(FREE SELF)**
-- Other [CI administration settings](../administration/index.md#cicd-settings).
 
 ## References
 
-### Why GitLab CI/CD?
-
-Learn more about:
+Learn more about GitLab CI/CD:
 
 - [Why you might choose GitLab CI/CD](https://about.gitlab.com/blog/2016/10/17/gitlab-ci-oohlala/).
 - [Reasons you might migrate from another platform](https://about.gitlab.com/blog/2016/07/22/building-our-web-app-on-gitlab-ci/).
@@ -151,10 +139,10 @@ Learn more about:
 
 See also the [Why CI/CD?](https://docs.google.com/presentation/d/1OGgk2Tcxbpl7DJaIOzCX4Vqg3dlwfELC3u2jEeCBbDk) presentation.
 
-### Breaking changes
+### Major version changes (breaking)
 
 As GitLab CI/CD has evolved, certain breaking changes have
-been necessary. These are:
+been necessary.
 
 #### 13.0
 

doc/ci/migration/jenkins.md

@@ -199,7 +199,7 @@ GitLab takes advantage of our connected ecosystem to automatically pull these ki
 your Merge Requests, pipeline details pages, and other locations. You may find that you actually don't
 need to configure anything to have these appear.
 
-If they aren't working as expected, or if you'd like to see what's available, our [CI feature index](../index.md#feature-set) has the full list
+If they aren't working as expected, or if you'd like to see what's available, our [CI feature index](../index.md#features) has the full list
 of bundled features and links to the documentation for each.
 
 ### Templates

doc/ci/quick_start/index.md

@@ -7,8 +7,7 @@ type: reference
 
 # Get started with GitLab CI/CD **(FREE)**
 
-Use this document to get started with
-GitLab [continuous integration](https://about.gitlab.com/stages-devops-lifecycle/continuous-integration/).
+Use this document to get started with [GitLab CI/CD](../index.md).
 
 Before you start, make sure you have: