update docs

Author: geof90

README.md

@@ -1,6 +1,6 @@
 # React Native Module for CodePush
 
-*Note: This README is only relevant to the latest version of our plugin in source. If you are using an older version, please switch to the relevant tag to view the docs for that particular version.*
+*Note: This README is only relevant to the latest version of our plugin. If you are using an older version, please switch to the relevant tag on [our GitHub repo](https://github.com/Microsoft/react-native-code-push) to view the docs for that particular version.*
 
 ![Switching tags](https://cloud.githubusercontent.com/assets/8598682/17350832/ce0dec40-58de-11e6-9c8c-906bb114c34f.png)