new read me

git-svn-id: https://plugins.svn.wordpress.org/instant-butler/trunk@833359 b8457f37-d9ea-0310-8a92-e5e31aec5664
added new screenshot - responsive!

git-svn-id: https://plugins.svn.wordpress.org/instant-butler/trunk@833361 b8457f37-d9ea-0310-8a92-e5e31aec5664