updated read me tags

git-svn-id: https://plugins.svn.wordpress.org/pure-chat/trunk@999514 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updated screenshots

git-svn-id: https://plugins.svn.wordpress.org/pure-chat/trunk@999515 b8457f37-d9ea-0310-8a92-e5e31aec5664