Added support for fetching latest release from GitLab (#7418)

* Fetch version for GitLab repositories

* Update documentation about repositories

* Fix code formatting

docs/setup/adding-a-git-repository.md

@@ -22,20 +22,25 @@ repo_url: https://github.com/squidfunk/mkdocs-material
 
 The link to the repository will be rendered next to the search bar on big
 screens and as part of the main navigation drawer on smaller screen sizes.
-Additionally, for public repositories hosted on [GitHub] or [GitLab], the
-number of stars and forks is automatically requested and rendered.
 
-GitHub repositories also include the tag of the latest release.[^1]
+Additionally, for public repositories hosted on [GitHub] or [GitLab], the
+latest release tag[^1], as well as the number of stars and forks, are
+automatically requested and rendered.
 
   [^1]:
     Unfortunately, GitHub only provides an API endpoint to obtain the [latest
     release] - not the latest tag. Thus, make sure to [create a release] (not
     pre-release) for the latest tag you want to display next to the number of
-    stars and forks.
+    stars and forks. For GitLab, although it is possible to get a [list of tags
+    sorted by update time], the [equivalent API endpoint] is used. So, make sure
+    you also [create a release for GitLab repositories].
 
   [repo_url]: https://www.mkdocs.org/user-guide/configuration/#repo_url
   [latest release]: https://docs.github.com/en/rest/reference/releases#get-the-latest-release
   [create a release]: https://docs.github.com/en/repositories/releasing-projects-on-github/managing-releases-in-a-repository#creating-a-release
+  [list of tags sorted by update time]: https://docs.gitlab.com/ee/api/tags.html#list-project-repository-tags
+  [equivalent API endpoint]: https://docs.gitlab.com/ee/api/releases/#get-the-latest-release
+  [create a release for GitLab repositories]: https://docs.gitlab.com/ee/user/project/releases/#create-a-release
 
 #### Repository name