added missing function okToGreet

src/ng/q.js

@@ -18,6 +18,10 @@
  * <pre>
  *   // for the purpose of this example let's assume that variables `$q` and `scope` are
  *   // available in the current lexical scope (they could have been injected or passed in).
+ * 
+ *   function okToGreet(name) {
+ *     return (name == 'Robin Hood');
+ *   }
  *
  *   function asyncGreet(name) {
  *     var deferred = $q.defer();