Add game_template (#1180)

Adds a template / sample for games built in Flutter, with all the bells and whistles, like ads, in-app purchases, audio, main menu, settings, and so on.

Co-authored-by: Parker Lougheed
Co-authored-by: Shams Zakhour

game_template/lib/src/audio/songs.dart

@@ -0,0 +1,24 @@
+// Copyright 2022, the Flutter project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+const Set<Song> songs = {
+  // Filenames with whitespace break package:audioplayers on iOS
+  // (as of February 2022), so we use no whitespace.
+  Song('Mr_Smith-Azul.mp3', 'Azul', artist: 'Mr Smith'),
+  Song('Mr_Smith-Sonorus.mp3', 'Sonorus', artist: 'Mr Smith'),
+  Song('Mr_Smith-Sunday_Solitude.mp3', 'SundaySolitude', artist: 'Mr Smith'),
+};
+
+class Song {
+  final String filename;
+
+  final String name;
+
+  final String? artist;
+
+  const Song(this.filename, this.name, {this.artist});
+
+  @override
+  String toString() => 'Song<$filename>';
+}