typo in readme

git-svn-id: https://plugins.svn.wordpress.org/directedit/trunk@964543 b8457f37-d9ea-0310-8a92-e5e31aec5664
several fixes

git-svn-id: https://plugins.svn.wordpress.org/directedit/trunk@964545 b8457f37-d9ea-0310-8a92-e5e31aec5664