feat: Added RouterComponent

doc/flame/examples/lib/main.dart

@@ -1,6 +1,7 @@
 import 'dart:html'; // ignore: avoid_web_libraries_in_flutter
 
 import 'package:doc_flame_examples/drag_events.dart';
+import 'package:doc_flame_examples/navigator.dart';
 import 'package:doc_flame_examples/tap_events.dart';
 import 'package:flame/game.dart';
 import 'package:flutter/widgets.dart';
@@ -18,6 +19,9 @@ void main() {
     case 'drag_events':
       game = DragEventsGame();
       break;
+    case 'navigator':
+      game = NavigatorGame();
+      break;
   }
   if (game != null) {
     runApp(GameWidget(game: game));