Fixed broken links in documentation (grafana#44044)

* Fixed broken link

* Fixed broken contribute documentation link

* Consistent relative contribute-folder url

Author: ToTheMax

CONTRIBUTING.md

@@ -80,6 +80,6 @@ Before we can accept your pull request, you need to [sign our CLA](https://grafa
 ## Where do I go from here?
 
 - Set up your [development environment](contribute/developer-guide.md).
-- Learn how to [contribute documentation](contribute/documentation.md).
+- Learn how to [contribute documentation](contribute/README.md).
 - Get started [developing plugins](https://grafana.com/docs/grafana/latest/developers/plugins/) for Grafana.
-- Look through the resources in the [contribute](https://github.com/grafana/grafana/tree/main/contribute) folder.
+- Look through the resources in the [contribute](contribute) folder.

docs/sources/administration/configuration.md

@@ -631,7 +631,7 @@ Path to the default home dashboard. If this value is empty, then Grafana uses St
 
 Set to `false` to prohibit users from being able to sign up / create
 user accounts. Default is `false`. The admin user can still create
-users from the [Grafana Admin Pages](/reference/admin).
+users from the [Grafana Admin Pages]({{< relref "../manage-users/server-admin/server-admin-manage-users.md" >}}).
 
 ### allow_org_create