Break 2d stuff into separate namespace

src/play_clj/ui.clj

@@ -1,5 +1,6 @@
 (ns play-clj.ui
-  (:require [play-clj.utils :as u])
+  (:require [play-clj.g2d :as g2d]
+            [play-clj.utils :as u])
   (:import [com.badlogic.gdx Files Gdx]
            [com.badlogic.gdx.graphics Color Texture]
            [com.badlogic.gdx.graphics.g2d BitmapFont TextureRegion]
@@ -14,6 +15,9 @@
             TiledDrawable]
            [com.esotericsoftware.tablelayout Cell]))
 
+; temporary inclusion to prevent breaking the template
+(defonce draw! g2d/draw!)
+
 (defmacro drawable
   [type & options]
   `(~(symbol (str u/main-package ".scenes.scene2d.ui."