added webstore url in README

README

@@ -1,6 +1,7 @@
+On Chrome webstore at https://chrome.google.com/webstore/detail/gadbenpggeagjgnameagcpjnjdlckkpb
 
 ==Test instructions==
 
 1) Clone this repository into a directory (Not a Git user? The download the ZIP - https://github.com/sajal/Cloudfront-Purge-Tool/zipball/master and unpack on your computer  )
 2) Load this directory as a chrome extension (Instructions: http://code.google.com/chrome/extensions/getstarted.html#load step 4 )
-3) Login using your AWS Access key ID and Secret Access Key
+3) Login using your AWS Access key ID and Secret Access Key