docs: improved OnRoomsRegistered

JotunnLib/Managers/DungeonManager.cs

@@ -31,7 +31,7 @@ public class DungeonManager : IManager
         public static event Action OnVanillaRoomsAvailable;
 
         /// <summary>
-        ///     Event that gets fired when the vanilla <see cref="DungeonDB"/> registers rooms.  Your code will execute
+        ///     Event that gets fired after all custom rooms are registered to the <see cref="DungeonDB"/>.  Your code will execute
         ///     every time a main scene is started (on joining a game). <br />
         ///     If you want to execute just once you will need to unregister from the event after execution.
         /// </summary>