[Security] Document the delete_cookies option

Author: javiereguiluz

reference/configuration/security.rst

@@ -30,6 +30,7 @@ Configuration
 * `access_denied_url`_
 * `always_authenticate_before_granting`_
 * `anonymous`_
+* `delete_cookies`_
 * `erase_credentials`_
 * `hide_user_not_found`_
 * `session_fixation_strategy`_
@@ -75,6 +76,13 @@ call in a template or ``isGranted()`` in a controller or service).
 
     The ``lazy`` value of the ``anonymous`` option was introduced in Symfony 4.4.
 
+delete_cookies
+~~~~~~~~~~~~~~
+
+**type**: ``array`` **default**: ``[]``
+
+Lists the names of the cookies to delete when the user logs out.
+
 erase_credentials
 ~~~~~~~~~~~~~~~~~