Removed invalid examples

Templating isn't a service in Symfony 4+ (even after `composer req templating`), so probably we're looking for the twig service.

The Router service isn't public and can therefor not be called from the container:
```
Information for Service "router.default"
========================================

 ---------------- -----------------------------------------------
  Option           Value
 ---------------- -----------------------------------------------
  Service ID       router.default
  Class            Symfony\Bundle\FrameworkBundle\Routing\Router
  Tags             -
  Calls            setConfigCacheFactory
  Public           no
  Synthetic        no
  Lazy             no
  Shared           yes
  Abstract         no
  Autowired        no
  Autoconfigured   no
 ---------------- -----------------------------------------------
```

Author: TheDevilOnLine

controller.rst

@@ -299,9 +299,7 @@ If you extend the base ``Controller`` class, you can access :ref:`public service
 via the :method:`Symfony\\Bundle\\FrameworkBundle\\Controller\\Controller::get`
 method. Here are several common services you might need::
 
-    $templating = $this->get('templating');
-
-    $router = $this->get('router');
+    $twig = $this->get('twig');
 
     $mailer = $this->get('mailer');