adding screenshot for plugin directory

git-svn-id: https://plugins.svn.wordpress.org/buddypress-foaf/trunk@842056 b8457f37-d9ea-0310-8a92-e5e31aec5664
adding screenshot for plugin directory

git-svn-id: https://plugins.svn.wordpress.org/buddypress-foaf/trunk@842058 b8457f37-d9ea-0310-8a92-e5e31aec5664