More changes to the Readme file

git-svn-id: https://plugins.svn.wordpress.org/wp-facebook-fanbox-widget/trunk@886850 b8457f37-d9ea-0310-8a92-e5e31aec5664
Added FAQ section to readme

git-svn-id: https://plugins.svn.wordpress.org/wp-facebook-fanbox-widget/trunk@886853 b8457f37-d9ea-0310-8a92-e5e31aec5664