Merge branch '5.0'

* 5.0:
  Minor tweak
  [Notifier] Add section Disabling Delivery

Author: javiereguiluz

notifier.rst

@@ -568,6 +568,24 @@ and
 :class:`Symfony\\Component\\Notifier\\Notification\\EmailNotificationInterface`
 also exists to modify messages send to those channels.
 
+Disabling Delivery
+------------------
+
+While developing (or testing), you may want to disable delivery of notifications
+entirely. You can do this by forcing Notifier to use the ``NullTransport`` for
+all configured texter and chatter transports only in the ``dev`` (and/or
+``test``) environment:
+
+.. code-block:: yaml
+
+    # config/packages/dev/notifier.yaml
+    framework:
+        notifier:
+            texter_transports:
+                twilio: 'null://null'
+            chatter_transports:
+                slack: 'null://null'
+
 .. TODO
     - Using the message bus for asynchronous notification
     - Describe notifier monolog handler