fixed some formatting issues within the readme file

git-svn-id: https://plugins.svn.wordpress.org/wp-social-seo-booster/trunk@756633 b8457f37-d9ea-0310-8a92-e5e31aec5664
re-arranged readme content

git-svn-id: https://plugins.svn.wordpress.org/wp-social-seo-booster/trunk@756634 b8457f37-d9ea-0310-8a92-e5e31aec5664