Factor out AnimatableTile{Factory}

js/animatable_tile_factory.js

@@ -0,0 +1,11 @@
+import { TileFactory } from './tile_factory.js';
+export class AnimatableTileFactory extends TileFactory {
+    constructor() {
+        super(...arguments);
+        this.animations = new Map();
+    }
+    add_animation(name, keyframes, options) {
+        this.animations.set(name, [keyframes, options]);
+    }
+}
+//# sourceMappingURL=animatable_tile_factory.js.map