Retrofit on "mentors" (admins with no perm except +ADMINHELP) (#5626)

Co-authored-by: Leon Friedrich <60421075+ElectroJr@users.noreply.github.com>

Content.Shared/Administration/AdminFlags.cs

@@ -75,6 +75,11 @@ namespace Content.Shared.Administration
         /// </summary>
         Query = 1 << 11,
 
+        /// <summary>
+        ///     Lets you use the admin help system.
+        /// </summary>
+        Adminhelp = 1 << 12,
+
         /// <summary>
         ///     Dangerous host permissions like scsi.
         /// </summary>