update description


git-svn-id: https://plugins.svn.wordpress.org/ridiculously-responsive-social-sharing-buttons/trunk@873077 b8457f37-d9ea-0310-8a92-e5e31aec5664
fixed typo

git-svn-id: https://plugins.svn.wordpress.org/ridiculously-responsive-social-sharing-buttons/trunk@873078 b8457f37-d9ea-0310-8a92-e5e31aec5664