Add comment pertaining to why Schedule() is required

osu.Game/OsuGame.cs

@@ -277,6 +277,9 @@ namespace osu.Game
         private void loadComponentSingleFile<T>(T d, Action<T> add)
             where T : Drawable
         {
+            // schedule is here to ensure that all component loads are done after LoadComplete is run (and thus all dependencies are cached).
+            // with some better organisation of LoadComplete to do construction and dependency caching in one step, followed by calls to loadComponentSingleFile,
+            // we could avoid the need for scheduling altogether.
             Schedule(() => { asyncLoadStream = asyncLoadStream?.ContinueWith(t => LoadComponentAsync(d, add).Wait()) ?? LoadComponentAsync(d, add); });
         }