Added screenshots

git-svn-id: https://plugins.svn.wordpress.org/bigbluebutton/trunk@885271 b8457f37-d9ea-0310-8a92-e5e31aec5664
Updated screenshots

git-svn-id: https://plugins.svn.wordpress.org/bigbluebutton/trunk@885272 b8457f37-d9ea-0310-8a92-e5e31aec5664