message: Add documentattion
diff: @@ -539,6 +539,28 @@ var attachment = {
  ```
  +## Message Tags
  +
  +Adding a tag to a message allows you to send it outside the 24+1 window.
  +
  +View the facebook [documentation](https://developers.facebook.com/docs/messenger-platform/messenger-profile/home-url) for more details.
  +
  +- Get all tags :
  +```javascript
  +controller.api.tags.get_all(function (tags) {
  + // use tags.data
  +});
  +```
  +
  +- Send a tagged message :
  +```javascript
  +var taggedMessage = {
  + "text": "Hello Botkit !",
  + "tag": "RESERVATION_UPDATE"
  +};
  +bot.reply(message, taggedMessage);
  +```
  +
  ## Use BotKit for Facebook Messenger with an Express web server
  Instead of the web server generated with setupWebserver(), it is possible to use a different web server to receive webhooks, as well as serving web pages.
  