feat(#15): separate sprite from player

modules/game-objects/index.js

@@ -4,3 +4,6 @@ export { FpsCounter } from "./fps-counter.js";
 export { GameObject } from "./game-object.js";
 export { MapManagement } from "./map-management.js";
 export { Map } from "./map.js";
+export { Player } from "./player.js";
+export { Sprite } from "./sprite.js";
+export { SpriteSheet } from "./sprite-sheet.js";