Fix up the docs warning detected by the vale Admin rule

doc/administration/troubleshooting/gitlab_rails_cheat_sheet.md

@@ -1279,7 +1279,7 @@ cluster = Clusters::Cluster.find_by(name: 'cluster_name')
 Delete cluster without associated resources:
 
 ```ruby
-# Find an admin user
+# Find users with the Administrator role
 user = User.find_by(username: 'admin_user')
 
 # Find the cluster with the ID

doc/administration/troubleshooting/linux_cheat_sheet.md

@@ -14,7 +14,7 @@ having an issue with GitLab, you may want to check your [support options](https:
 first, before attempting to use this information.
 
 WARNING:
-If you are administering GitLab you are expected to know these commands for your distribution
+If you administer GitLab you are expected to know these commands for your distribution
 of choice. If you are a GitLab Support Engineer, consider this a cross-reference to
 translate `yum` -> `apt-get` and the like.