[Security] document current user attribute in the main security doc entry

Author: 94noni

security.rst

@@ -2082,6 +2082,7 @@ accessed via the ``getUser()`` shortcut in the
 
     use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
     use Symfony\Component\HttpFoundation\Response;
+    use Symfony\Component\Security\Http\Attribute\CurrentUser;
 
     class ProfileController extends AbstractController
     {
@@ -2100,6 +2101,11 @@ accessed via the ``getUser()`` shortcut in the
             // For example, if you added a getFirstName() method, you can use that.
             return new Response('Well hi there '.$user->getFirstName());
         }
+
+        public function me(#[CurrentUser] User $user): Response
+        {
+            // $user is an instance of \App\Entity\User
+        }
     }
 
 Fetching the User from a Service