Update readme

Swapping out broken images for links to docs

Author: satchkat

README.md

@@ -56,7 +56,8 @@ This project is built using [Ruby on Rails](http://rubyonrails.org/) Framework f
    sms:   http://9a159ccf.ngrok.io/message/incoming
    ```
 
-   ![Configure webhooks](http://howtodocs.s3.amazonaws.com/twilio-number-config-all-med.gif)
+   [Learn how to configure a Twilio phone number for Programmable Voice](https://www.twilio.com/docs/voice/quickstart/ruby#configure-your-webhook-url)
+   [Learn how to configure a Twilio phone number for Programmable SMS](https://support.twilio.com/hc/en-us/articles/223136047-Configure-a-Twilio-Phone-Number-to-Receive-and-Respond-to-Messages)
 
 1. Copy the sample configuration file and edit it to match your configuration.