5.3.7 better doc and bug fixes

git-svn-id: https://plugins.svn.wordpress.org/jm-twitter-cards/trunk@1006093 b8457f37-d9ea-0310-8a92-e5e31aec5664
add svn

git-svn-id: https://plugins.svn.wordpress.org/jm-twitter-cards/trunk@1006094 b8457f37-d9ea-0310-8a92-e5e31aec5664