modified readme.txt

git-svn-id: https://plugins.svn.wordpress.org/automatic-quotes/trunk@879406 b8457f37-d9ea-0310-8a92-e5e31aec5664
checking

git-svn-id: https://plugins.svn.wordpress.org/automatic-quotes/trunk@879410 b8457f37-d9ea-0310-8a92-e5e31aec5664