Explain the available docker images

README.md

@@ -93,12 +93,23 @@ Host your docker container at [sloppy.io](http://sloppy.io). Get an account and
 
 or
 
-Use the automated build at our [Official Docker Registry](https://hub.docker.com/r/rocketchat/rocket.chat/)
+Use the automated build image of our [most recent in-development code](https://hub.docker.com/r/rocketchat/rocket.chat/)
 
 [![Rocket.Chat logo](https://d207aa93qlcgug.cloudfront.net/1.95.5.qa/img/nav/docker-logo-loggedout.png)](https://hub.docker.com/r/rocketchat/rocket.chat/)
 
 ```
-docker pull rocketchat/rocket.chat
+docker pull rocketchat/rocket.chat:develop
+```
+
+OR the latest available stable (master) branch code:
+```
+docker pull rocketchat/rocket.chat:lastest
+```
+
+OR our [official docker registry image](https://hub.docker.com/_/rocket.chat/), containing recent MAJOR release:
+
+```
+docker pull rocket.chat
 ```
 
 ## FreeBSD