Add link

TUTORIAL.md

@@ -190,7 +190,7 @@ Now, when you resize your game, the image is no longer stretched!
 
 ## Java Interop
 
-At some point, you will need to do more than simple positioning and sizing. For that, you'll need to call LibGDX methods directly. You could, of course, use Clojure's Java interop syntax on the `:object` contained within the entity. This is a bit ugly, though, and requires you to do all the importing and type hinting yourself.
+At some point, you will need to do more than simple positioning and sizing. For that, you'll need to call LibGDX methods directly. You could, of course, use Clojure's [Java interop](http://clojure.org/java_interop) syntax on the `:object` contained within the entity. This is a bit ugly, though, and requires you to do all the importing and type hinting yourself.
 
 In play-clj, anything that creates an entity, such as `texture`, is actually a macro that allows you to call the underlying Java methods after the required argument(s). In this case, the underlying class is called [TextureRegion](http://libgdx.badlogicgames.com/nightlies/docs/api/com/badlogic/gdx/graphics/g2d/TextureRegion.html). Consider this: