update faq on readme

git-svn-id: https://plugins.svn.wordpress.org/si-contact-form/trunk@781011 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme

git-svn-id: https://plugins.svn.wordpress.org/si-contact-form/trunk@781012 b8457f37-d9ea-0310-8a92-e5e31aec5664