docs($q): implement the same example for constructor as deferred

The current documentation has a `return` in the middle of nowhere and somewhat complicates the example with unnecessary code. This implements the same code as in the example for the other way of using $q in order to simplify the differences between them.

Author: James Kleeh

src/ng/q.js

@@ -23,24 +23,27 @@
  * It can be used like so:
  *
  * ```js
- * return $q(function(resolve, reject) {
- *   // perform some asynchronous operation, resolve or reject the promise when appropriate.
- *   setInterval(function() {
- *     if (pollStatus > 0) {
- *       resolve(polledValue);
- *     } else if (pollStatus < 0) {
- *       reject(polledValue);
- *     } else {
- *       pollStatus = pollAgain(function(value) {
- *         polledValue = value;
- *       });
- *     }
- *   }, 10000);
- * }).
- *   then(function(value) {
- *     // handle success
+ *   // for the purpose of this example let's assume that variables `$q` and `okToGreet`
+ *   // are available in the current lexical scope (they could have been injected or passed in).
+ *
+ *   function asyncGreet(name) {
+ *     // perform some asynchronous operation, resolve or reject the promise when appropriate.
+ *     return $q(function(resolve, reject) {
+ *       setTimeout(function() {
+ *         if (okToGreet(name)) {
+ *           resolve('Hello, ' + name + '!');
+ *         } else {
+ *           reject('Greeting ' + name + ' is not allowed.');
+ *         }
+ *       }, 1000);
+ *     });
+ *   }
+ *
+ *   var promise = asyncGreet('Robin Hood');
+ *   promise.then(function(greeting) {
+ *     alert('Success: ' + greeting);
  *   }, function(reason) {
- *     // handle failure
+ *     alert('Failed: ' + reason);
  *   });
  * ```
  *
@@ -56,7 +59,7 @@
  * asynchronous programming what `try`, `catch` and `throw` keywords are to synchronous programming.
  *
  * ```js
- *   // for the purpose of this example let's assume that variables `$q`, `scope` and `okToGreet`
+ *   // for the purpose of this example let's assume that variables `$q` and `okToGreet`
  *   // are available in the current lexical scope (they could have been injected or passed in).
  *
  *   function asyncGreet(name) {