Update readme menu

Author: Christoph Rumpel

README.md

@@ -16,7 +16,9 @@ This package makes it easy to send notifications using [Twitter](https://dev.twi
 - [Installation](#installation)
 	- [Setting up the Twitter service](#setting-up-the-Twitter-service)
 - [Usage](#usage)
-	- [Available Message methods](#available-message-methods)
+	- [Publish Twitter status update](#publish-twitter-status-update)
+	- [Publish Twitter status update with images](#publish-twitter-status-spdate-with-images)
+ - [Send a direct message](#send-a-direct-message)
 - [Changelog](#changelog)
 - [Testing](#testing)
 - [Security](#security)