read me - added migration and support for 2.* versions

Author: mithunsatheesh

README.md

@@ -15,7 +15,7 @@ install node-rules via npm
 
     npm install node-rules
 
-*We have improved the API in the 3.0.0 version, if you were using the v2.2.2, please find the relevant docs and code base [here](https://github.com/mithunsatheesh/node-rules/tree/v2.2.3). To migrate to 3.0.0 please  read [the wiki here](https://github.com/mithunsatheesh/node-rules/wiki)!*
+*We have improved the API in the 3.x.x version, if you were using the v2.x.x, please find the relevant docs and code base [here](https://github.com/mithunsatheesh/node-rules/tree/v2.2.3). To migrate to 3.0.0 please  read [the wiki here](https://github.com/mithunsatheesh/node-rules/wiki)!*
 
 
 ####Overview