refactor: extract bubble-game engine as independent package

packages/misskey-bubble-game/src/index.ts

@@ -0,0 +1,10 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and other misskey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { DropAndFusionGame, Mono } from './game.js';
+
+export {
+	DropAndFusionGame, Mono,
+};