Bring feature flag docs up to spec

If we're editing these lines, let's bring them completely up to the
current feature flag spec.

doc/user/project/merge_requests/commits.md

@@ -29,21 +29,17 @@ To seamlessly navigate among commits in a merge request:
 
 ## View merge request commits in context
 
-> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/29274) in GitLab 13.12.
-> - [Deployed behind a feature flag](../../feature_flags.md), enabled by default.
-> - Disabled on GitLab.com.
-> - Not recommended for production use.
-> - To use in GitLab self-managed instances, ask a GitLab administrator to [enable it](#enable-or-disable-viewing-merge-request-commits-in-context).
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/29274) in GitLab 13.12 [with a flag](../../../administration/feature_flags.md) named `context_commits`. Enabled by default.
+> - [Enabled on GitLab.com](https://gitlab.com/gitlab-org/gitlab/-/issues/320757) in GitLab 14.8.
 
 WARNING:
 This feature is in [beta](../../../policy/alpha-beta-support.md#beta-features)
 and is [incomplete](https://gitlab.com/groups/gitlab-org/-/epics/1192).
-Previously merged commits can be added, but they can't be removed due to
-[this bug](https://gitlab.com/gitlab-org/gitlab/-/issues/325538).
 
-This in-development feature might not be available for your use. There can be
-[risks when enabling features still in development](../../../administration/feature_flags.md#risks-when-enabling-features-still-in-development).
-Refer to this feature's version history for more details.
+FLAG:
+On self-managed GitLab, by default this feature is available. To hide the feature,
+ask an administrator to [disable the feature flag](../../../administration/feature_flags.md) named `context_commits`.
+On GitLab.com, this feature is available.
 
 When reviewing a merge request, it helps to have more context about the changes
 made. That includes unchanged lines in unchanged files, and previous commits
@@ -66,22 +62,3 @@ To view the changes done on those previously merged commits:
 1. Scroll to **(file-tree)** **Compare** and select **previously merged commits**:
 
    ![Previously merged commits](img/previously_merged_commits_v14_1.png)
-
-### Enable or disable viewing merge request commits in context **(FREE SELF)**
-
-Viewing merge request commits in context is under development and not ready for production use. It is
-deployed behind a feature flag that is **disabled by default**.
-[GitLab administrators with access to the GitLab Rails console](../../../administration/feature_flags.md)
-can enable it.
-
-To enable it:
-
-```ruby
-Feature.enable(:context_commits)
-```
-
-To disable it:
-
-```ruby
-Feature.disable(:context_commits)
-```