Add additional feature flag details

doc/administration/feature_flags.md

@@ -36,7 +36,7 @@ For example, data is not recorded and services do not run.
 If you used a certain feature and identified a bug, a misbehavior, or an
 error, it's very important that you [**provide feedback**](https://gitlab.com/gitlab-org/gitlab/-/issues/new?issue[title]=Docs%20-%20feature%20flag%20feedback%3A%20Feature%20Name&issue[description]=Describe%20the%20problem%20you%27ve%20encountered.%0A%0A%3C!--%20Don%27t%20edit%20below%20this%20line%20--%3E%0A%0A%2Flabel%20~%22docs%5C-comments%22%20) to GitLab as soon
 as possible so we can improve or fix it while behind a flag. When you upgrade
-GitLab to an earlier version, the feature flag status may change.
+GitLab, the feature flag status may change.
 
 ## Risks when enabling features still in development
 
@@ -144,3 +144,24 @@ Feature.enabled?(:my_awesome_feature)
 Feature.disabled?(:my_awesome_feature)
 => false
 ```
+
+When the feature is ready, GitLab removes the feature flag, and the option for
+enabling and disabling it no longer exists. The feature becomes available in all instances.
+
+### View set feature flags
+
+You can view all GitLab administrator set feature flags:
+
+```ruby
+Feature.all
+=> [#<Flipper::Feature:198220 name="my_awesome_feature", state=:on, enabled_gate_names=[:boolean], adapter=:memoizable>]
+```
+
+### Unset feature flag
+
+You can unset a feature flag so that GitLab will fall back to the current defaults for that flag:
+
+```ruby
+Feature.remove(:my_awesome_feature)
+=> true
+```