Merge branch '2.8' into 3.4

* 2.8:
  fix the markup
  Changing to absolute url, as requested
  Updated link to Event Listeners page
  Revert "Fix typo on which YAML values must not be quoted"
  Fix typo on which YAML values must not be quoted

Author: weaverryan

doctrine/event_listeners_subscribers.rst

@@ -240,4 +240,4 @@ to the tag like so:
     definitions which are described :doc:`in their own article </service_container/lazy_services>`
 
 .. _`The Event System`: http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/events.html
-.. _`the Doctrine Documentation`: http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/events.html#entity-listeners
+.. _`the Doctrine Documentation`: https://symfony.com/doc/current/bundles/DoctrineBundle/entity-listeners.html