Clean up two feature flag docs for Source Code

Bring two more of the items mentioning feature flags up to our
current style spec in our docs.

doc/user/project/repository/branches/default.md

@@ -57,8 +57,8 @@ GitLab administrators can configure a new default branch name at the
 
 ### Instance-level custom initial branch name **(FREE SELF)**
 
-> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/221013) in GitLab 13.2.
-> - [Feature flag removed](https://gitlab.com/gitlab-org/gitlab/-/issues/325163) in GitLab 13.12.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/221013) in GitLab 13.2 [with a flag](../../../../administration/feature_flags.md) named `global_default_branch_name`. Enabled by default.
+> - [Generally available](https://gitlab.com/gitlab-org/gitlab/-/issues/325163) in GitLab 13.12. Feature flag `global_default_branch_name` removed.
 
 GitLab [administrators](../../../permissions.md) of self-managed instances can
 customize the initial branch for projects hosted on that instance. Individual

doc/user/project/repository/forking_workflow.md

@@ -33,7 +33,7 @@ To fork an existing project in GitLab:
      ![Choose namespace](img/forking_workflow_choose_namespace_v13_10.png)
 
    - Experimental method. If your GitLab administrator has
-     [enabled the experimental fork project form](#enable-or-disable-the-fork-project-form), read
+     enabled the experimental fork project form, read
      [Create a fork with the fork project form](#create-a-fork-with-the-fork-project-form).
      Only namespaces where you have at least the Developer role for are shown.
 
@@ -84,14 +84,14 @@ You can unlink your fork from its upstream project in the [advanced settings](..
 
 ## Create a fork with the fork project form **(FREE SELF)**
 
-> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/15013) in GitLab 13.11.
-> - It's [deployed behind a feature flag](../../../user/feature_flags.md), disabled by default.
-> - It's disabled on GitLab.com.
-> - It's not recommended for production use.
-> - To use it in GitLab self-managed instances, ask a GitLab administrator to [enable it](#enable-or-disable-the-fork-project-form). **(FREE SELF)**
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/15013) in GitLab 13.11 [with a flag](../../../administration/feature_flags.md) named `fork_project_form`. Disabled by default.
+> - [Enabled on self-managed and GitLab.com](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/64967) in GitLab 13.8.
 
-This experimental version of the fork project form is available only if your GitLab
-administrator has [enabled it](#enable-or-disable-the-fork-project-form):
+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 `fork_project_form`.
+On GitLab.com, this feature is available.
+
+This version of the fork project form is experimental:
 
 ![Choose namespace](img/fork_form_v13_10.png)
 
@@ -102,23 +102,3 @@ To use it, follow the instructions at [Creating a fork](#creating-a-fork) and pr
 - The project slug.
 - Optional. The project description.
 - The visibility level for your fork.
-
-### Enable or disable the fork project form **(FREE SELF)**
-
-The new [fork project form](#create-a-fork-with-the-fork-project-form) 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(:fork_project_form)
-```
-
-To disable it:
-
-```ruby
-Feature.disable(:fork_project_form)
-```