screenshot added

git-svn-id: https://plugins.svn.wordpress.org/wordpress-meta-description/trunk@897344 b8457f37-d9ea-0310-8a92-e5e31aec5664
screenshot-2.gif changed

git-svn-id: https://plugins.svn.wordpress.org/wordpress-meta-description/trunk@897352 b8457f37-d9ea-0310-8a92-e5e31aec5664