message: Added information about Facebook endpoints
  We never stated where Botkit is listening for Facebook callbacks. Hopefully this clarifies the situation.
diff: @@ -28,6 +28,7 @@ Table of Contents
  2) Create a [Facebook App for Web](https://developers.facebook.com/quickstarts/?platform=web) and note down or [create a new Facebook Page](https://www.facebook.com/pages/create/). Your Facebook page will be used for the app's identity.
  +
  3) [Get a page access token for your app](https://developers.facebook.com/docs/messenger-platform/guides/setup#page_access_token)
  Copy this token, you'll need it!
  @@ -42,6 +43,8 @@ page_token=<MY PAGE TOKEN> verify_token=<MY_VERIFY_TOKEN> node facebook_bot.js [
  6) [Set up a webhook endpoint for your app](https://developers.facebook.com/docs/messenger-platform/guides/setup#webhook_setup) that uses your public URL. Use the verify token you defined in step 4!
  +* *Note* - You will need to provide Facebook a callback endpoint to receive requests from Facebook. By default Botkit will serve content from "https://YOURSERVER/facebook/receive". You can use a tool like [ngrok.io](http://ngrok.io) or [localtunnel.me](http://localtunnel.me) to expose your local development enviroment to the outside world for the purposes of testing your Messenger bot.
  +
  7) Your bot should be online! Within Facebook, find your page, and click the "Message" button in the header.
  Try:
  