readme update

git-svn-id: https://plugins.svn.wordpress.org/wpbase-video/trunk@762394 b8457f37-d9ea-0310-8a92-e5e31aec5664
reademe update

git-svn-id: https://plugins.svn.wordpress.org/wpbase-video/trunk@762396 b8457f37-d9ea-0310-8a92-e5e31aec5664