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/sounds.dart

@@ -0,0 +1,71 @@
+// 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.
+
+List<String> soundTypeToFilename(SfxType type) {
+  switch (type) {
+    case SfxType.huhsh:
+      return const [
+        'hash1.mp3',
+        'hash2.mp3',
+        'hash3.mp3',
+      ];
+    case SfxType.wssh:
+      return const [
+        'wssh1.mp3',
+        'wssh2.mp3',
+        'dsht1.mp3',
+        'ws1.mp3',
+        'spsh1.mp3',
+        'hh1.mp3',
+        'hh2.mp3',
+        'kss1.mp3',
+      ];
+    case SfxType.buttonTap:
+      return const [
+        'k1.mp3',
+        'k2.mp3',
+        'p1.mp3',
+        'p2.mp3',
+      ];
+    case SfxType.congrats:
+      return const [
+        'yay1.mp3',
+        'wehee1.mp3',
+        'oo1.mp3',
+      ];
+    case SfxType.erase:
+      return const [
+        'fwfwfwfwfw1.mp3',
+        'fwfwfwfw1.mp3',
+      ];
+    case SfxType.swishSwish:
+      return const [
+        'swishswish1.mp3',
+      ];
+  }
+}
+
+/// Allows control over loudness of different SFX types.
+double soundTypeToVolume(SfxType type) {
+  switch (type) {
+    case SfxType.huhsh:
+      return 0.4;
+    case SfxType.wssh:
+      return 0.2;
+    case SfxType.buttonTap:
+    case SfxType.congrats:
+    case SfxType.erase:
+    case SfxType.swishSwish:
+      return 1.0;
+  }
+}
+
+enum SfxType {
+  huhsh,
+  wssh,
+  buttonTap,
+  congrats,
+  erase,
+  swishSwish,
+}