minor #1446 Add notice to messenger for async code (94noni)

This PR was merged into the main branch.

Discussion
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Add notice to messenger for async code

While reading this, I found that pointing messenger here can be valuable (logic of decoupling)
Also, reading the code itself of the dispatch, I remind my old PR symfony/symfony-docs#17035
there is no doc referencing the new `->dispatch(new ClassName())` as far as I see in https://symfony.com/doc/current/components/event_dispatcher.html#dispatch-the-event

Commits
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3b7a46d Add notice to messenger for async code

Author: javiereguiluz

src/Controller/BlogController.php

@@ -123,6 +123,9 @@ public function commentNew(
             // passed in the event and they can even modify the execution flow, so
             // there's no guarantee that the rest of this controller will be executed.
             // See https://symfony.com/doc/current/components/event_dispatcher.html
+            // You can also leverage the Symfony Messenger component if you need
+            // some asynchronous operations.
+            // See https://symfony.com/doc/current/messenger.html
             $eventDispatcher->dispatch(new CommentCreatedEvent($comment));
 
             return $this->redirectToRoute('blog_post', ['slug' => $post->getSlug()]);