Modified readme file

git-svn-id: https://plugins.svn.wordpress.org/unique-headers/trunk@1049674 b8457f37-d9ea-0310-8a92-e5e31aec5664
More readme changes

git-svn-id: https://plugins.svn.wordpress.org/unique-headers/trunk@1049677 b8457f37-d9ea-0310-8a92-e5e31aec5664