Add some sound functionality

src/game/items/cup.js

@@ -0,0 +1,10 @@
+import ItemBuilder from "../../engine/builders/item";
+import Item from "../../engine/item";
+
+export default new ItemBuilder()
+.withID("cup")
+.withName("a cup")
+.withDescription("A standard coffee cup")
+.isTakeable(true)
+.isUsable(false)
+.create();