readme update

git-svn-id: https://plugins.svn.wordpress.org/nextgen-facebook/trunk@892343 b8457f37-d9ea-0310-8a92-e5e31aec5664
added comments

git-svn-id: https://plugins.svn.wordpress.org/nextgen-facebook/trunk@892345 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme update

git-svn-id: https://plugins.svn.wordpress.org/nextgen-facebook/trunk@892348 b8457f37-d9ea-0310-8a92-e5e31aec5664