Update RancherOS Documentation link

Author: sheng-liang

README.md

@@ -94,7 +94,7 @@ The image supports RancherOS cloud config functionality. Additionally, it merges
 
 ## Documentation for RancherOS
 
-Please refer to our [website](http://rancherio.github.io/os/) to read all about RancherOS. It has detailed information on how it works, getting-started and other details.
+Please refer to our [RancherOS Documentation](http://os.docs.rancher.com/) website to read all about RancherOS. It has detailed information on how RancherOS works, getting-started and other details.
 
 ## Support, Discussion, and Community
 If you need any help with RancherOS or Rancher, please join us at either our [rancherio Google Groups](https://groups.google.com/forum/#!forum/rancherio) or [#rancher IRC channel](http://webchat.freenode.net/?channels=rancher) where most of our team hangs out at.