Merge pull request RasaHQ#5978 from karen-white/patch-2

Explain how to set webhook URL

Author: erohmensing

docs/user-guide/connectors/twilio.rst

@@ -29,6 +29,11 @@ You need to set up a Twilio account.
      steps to connect a phone number to the project.
   3. Now you can use the ``Account SID``, ``Auth Token``, and the phone
      number you purchased in your ``credentials.yml``.
+  4. Configure your webhook URL by navigating to 
+     [Phone Numbers](https://www.twilio.com/console/phone-numbers/incoming) in the Twilio 
+     dashboard and selecting your phone number. Find the ``Messaging`` section and add 
+     your webhook URL (e.g. ``https://yyyyyy.ngrok.io/webhooks/twilio/webhook``) to the 
+     ``A MESSAGE COMES IN`` setting.
 
 For more information, see the `Twilio REST API <https://www.twilio.com/docs/iam/api>`_.