readme.txt change

git-svn-id: https://plugins.svn.wordpress.org/wp-responsive-thumbnail-slider/trunk@819868 b8457f37-d9ea-0310-8a92-e5e31aec5664
screenshot-6.png change

git-svn-id: https://plugins.svn.wordpress.org/wp-responsive-thumbnail-slider/trunk@819870 b8457f37-d9ea-0310-8a92-e5e31aec5664