[docs] Add docs about the bundle's profiler

Author: Maksym Kotliar

docs/bundle/debuging.md

@@ -1,3 +1,53 @@
 # Debugging
 
+## Profiler
+
+It may be useful to see what messages were sent during a http request. 
+The bundle provides a collector for Symfony [profiler](http://symfony.com/doc/current/profiler.html).
+The extension collects all sent messages
+
+To enable profiler
+
+```yaml
+# app/config/config_dev.yml
+
+enqueue:
+    client:
+        traceable_producer: true
+```
+
+Now suppose you have this code in an action:
+
+```php
+<?php
+
+use Symfony\Bundle\FrameworkBundle\Controller\Controller;
+use Symfony\Component\HttpFoundation\Request;
+use Enqueue\Client\Message;
+use Enqueue\Client\MessageProducerInterface;
+
+class DefaultController extends Controller 
+    /**
+     * @Route("/", name="homepage")
+     */
+    public function indexAction(Request $request)
+    {
+        /** @var MessageProducerInterface $producer */
+        $producer = $this->get('enqueue.message_producer'); 
+        
+        $producer->send('foo_topic', 'Hello world');
+        
+        $producer->send('bar_topic', ['bar' => 'val']);
+
+        $message = new Message();
+        $message->setBody('baz');
+        $producer->send('baz_topic', $message);
+
+        // ...
+    }
+
+```
+
+For this action you may see something like this in the profiler: 
+
 [back to index](../index.md)