Add challenge hoisting question.

Author: RyanMcG

index.html

@@ -275,6 +275,18 @@
 
             Well, almost...
           </section>
+          <section data-markdown>
+            ## Function definition crap
+
+                var y = function () { ... };
+                // What's the difference?
+                function y() { ... }
+          </section>
+          <section data-markdown>
+            ### Answer
+
+            Hoisting.
+          </section>
         </section>
       </div>
     </div>