Crop and resize images, revise text

Revise images: crop down to show only the new feature. Resize to fit
in our image guidelines. Rename to include version number.

Revise text to remove wordiness and bring closer to GitLab style.

doc/user/project/merge_requests/getting_started.md

@@ -62,7 +62,7 @@ request's page at the top-right side:
 - Enable the [squash commits when merge request is accepted](squash_and_merge.md) option to combine all the commits into one before merging, thus keep a clean commit history in your repository.
 - Set the merge request as a [**Draft**](work_in_progress_merge_requests.md) to avoid accidental merges before it is ready.
 
-Once you have created the merge request, you can also:
+After you have created the merge request, you can also:
 
 - [Discuss](../../discussions/index.md) your implementation with your team in the merge request thread.
 - [Perform inline code reviews](reviewing_and_managing_merge_requests.md#perform-inline-code-reviews).
@@ -70,7 +70,7 @@ Once you have created the merge request, you can also:
 - Preview continuous integration [pipelines on the merge request widget](reviewing_and_managing_merge_requests.md#pipeline-status-in-merge-requests-widgets).
 - Preview how your changes look directly on your deployed application with [Review Apps](reviewing_and_managing_merge_requests.md#live-preview-with-review-apps).
 - [Allow collaboration on merge requests across forks](allow_collaboration.md).
-- Perform a [Review](../../discussions/index.md#merge-request-reviews) in order to create multiple comments on a diff and publish them once you're ready.
+- Perform a [Review](../../discussions/index.md#merge-request-reviews) to create multiple comments on a diff and publish them when you're ready.
 - Add [code suggestions](../../discussions/index.md#suggest-changes) to change the content of merge requests directly into merge request threads, and easily apply them to the codebase directly from the UI.
 - Add a time estimation and the time spent with that merge request with [Time Tracking](../time_tracking.md#time-tracking).
 
@@ -161,6 +161,53 @@ Feature.disable(:merge_request_reviewers)
 Feature.disable(:merge_request_reviewers, Project.find(<project id>))
 ```
 
+#### Reviewer approval rules
+
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/233736) in GitLab 13.8.
+> - It was [deployed behind a feature flag](../../../user/feature_flags.md), disabled by default.
+> - [Became enabled by default](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/51183) in GitLab 13.8.
+> - It's enabled on GitLab.com.
+> - It's recommended for production use.
+> - It can be enabled or disabled for a single project.
+> - For GitLab self-managed instances, GitLab administrators can opt to [disable it](#enable-or-disable-reviewer-approval-rules). **(CORE ONLY)**
+
+When editing the **Reviewers** field in a new or existing merge request, this feature
+displays the name of the matching [approval rule](merge_request_approvals.md#approval-rules)
+below the name of each suggested reviewer. [Code Owners](../code_owners.md) are displayed as `Codeowner` without group detail. We intend to iterate on this feature in future releases.
+
+This example shows reviewers and approval rules when creating a new merge request:
+
+![Reviewer approval rules in new/edit form](img/reviewer_approval_rules_form_v13_8.png)
+
+This example shows reviewers and approval rules in a merge request sidebar:
+
+![Reviewer approval rules in sidebar](img/reviewer_approval_rules_sidebar_v13_8.png)
+
+##### Enable or disable Reviewer Approval Rules **(CORE ONLY)**
+
+Merge Request Reviewers is under development and ready for production use.
+It is deployed behind a feature flag that is **enabled by default**.
+[GitLab administrators with access to the GitLab Rails console](../../../administration/feature_flags.md)
+can opt to disable it.
+
+To enable it:
+
+```ruby
+# For the instance
+Feature.enable(:reviewer_approval_rules)
+# For a single project
+Feature.enable(:reviewer_approval_rules, Project.find(<project id>))
+```
+
+To disable it:
+
+```ruby
+# For the instance
+Feature.disable(:reviewer_approval_rules)
+# For a single project
+Feature.disable(:reviewer_approval_rules, Project.find(<project id>))
+```
+
 ### Merge requests to close issues
 
 If the merge request is being created to resolve an issue, you can
@@ -200,5 +247,5 @@ is set for deletion, the merge request widget displays the
   at once. By doing so, you save pipeline minutes.
 - Delete feature branches on merge or after merging them to keep your repository clean.
 - Take one thing at a time and ship the smallest changes possible. By doing so,
-  you'll have faster reviews and your changes will be less prone to errors.
+  reviews are faster and your changes are less prone to errors.
 - Do not use capital letters nor special chars in branch names.