readme update

git-svn-id: https://plugins.svn.wordpress.org/easy-media-gallery/trunk@923584 b8457f37-d9ea-0310-8a92-e5e31aec5664
update download count

git-svn-id: https://plugins.svn.wordpress.org/easy-media-gallery/trunk@923587 b8457f37-d9ea-0310-8a92-e5e31aec5664