update readme

git-svn-id: https://plugins.svn.wordpress.org/content-syndication-toolkit/trunk@1056506 b8457f37-d9ea-0310-8a92-e5e31aec5664
update readme

git-svn-id: https://plugins.svn.wordpress.org/content-syndication-toolkit/trunk@1056510 b8457f37-d9ea-0310-8a92-e5e31aec5664