fix: stopped allowing F1 to create more than one help dialog window in the Charting Editor

Author: amyspark-ng

source/funkin/ui/debug/charting/ChartEditorState.hx

@@ -5654,7 +5654,9 @@ class ChartEditorState extends UIState // UIState derives from MusicBeatState
   function handleHelpKeybinds():Void
   {
     // F1 = Open Help
-    if (FlxG.keys.justPressed.F1) this.openUserGuideDialog();
+    if (FlxG.keys.justPressed.F1 && !isHaxeUIDialogOpen) {
+      this.openUserGuideDialog();
+    }
   }
 
   function handleQuickWatch():Void