Docs: updates for file-based menu (#28500)

* initial

* cleanup

* remove bad aliases

* cleanup, fix links

* add docs-file-based-command

* update docs

* update readme

* fix broken links

* fix spelling

Co-authored-by: Diana Payton <52059945+oddlittlebird@users.noreply.github.com>

docs/sources/auth/gitlab.md

@@ -2,11 +2,6 @@
 title = "GitLab OAuth2 Authentication"
 description = "Grafana OAuthentication Guide "
 keywords = ["grafana", "configuration", "documentation", "oauth"]
-type = "docs"
-[menu.docs]
-name = "GitLab"
-identifier = "gitlab_oauth"
-parent = "authentication"
 weight = 900
 +++
 
@@ -58,7 +53,7 @@ api_url = https://gitlab.com/api/v4
 allowed_groups =
 ```
 
-You may have to set the `root_url` option of `[server]` for the callback URL to be 
+You may have to set the `root_url` option of `[server]` for the callback URL to be
 correct. For example in case you are serving Grafana behind a proxy.
 
 Restart the Grafana backend for your changes to take effect.
@@ -121,7 +116,7 @@ allowed_groups = example, foo/bar
 > Only available in Grafana Enterprise v6.4+
 
 With Team Sync you can map your GitLab groups to teams in Grafana so that your users will automatically be added to
-the correct teams. 
+the correct teams.
 
 Your GitLab groups can be referenced in the same way as `allowed_groups`, like `example` or `foo/bar`.