Apply suggestions from code review

Author: AlbertMorenoDEV

mailer.rst

@@ -220,7 +220,7 @@ Custom Transport Factories
 
 There is a way to easily create your own custom transport factory in case you need to do something special creating the actual transport.
 
-The new factory needs to implement `Symfony\Component\Mailer\Transport\TransportFactoryInterface`. To remove some boilerplate you can even extend from `Symfony\Component\Mailer\Transport\AbstractTransportFactory` which will simplify the new factory:
+The new factory needs to implement :class:`Symfony\\Component\\Mailer\\Transport\\TransportFactoryInterface`. To remove some boilerplate you can even extend from :class:`Symfony\\Component\\Mailer\\Transport\\AbstractTransportFactory` which will simplify the new factory:
 
 .. code-block:: php
     
@@ -254,7 +254,7 @@ Finally, declare the new factory in setting tag the tag `mailer.transport_factor
 
         <!-- config/services.xml -->
         <service id="mailer.transport_factory.custom" class="App\CustomTransportFactory" parent="mailer.transport_factory.abstract">
-            <tag name="mailer.transport_factory" />
+            <tag name="mailer.transport_factory"/>
         </service>
 
     .. code-block:: php