added new shortcode

git-svn-id: https://plugins.svn.wordpress.org/bbpress-like-topics/trunk@1031823 b8457f37-d9ea-0310-8a92-e5e31aec5664
added new shortcode

git-svn-id: https://plugins.svn.wordpress.org/bbpress-like-topics/trunk@1031824 b8457f37-d9ea-0310-8a92-e5e31aec5664