Refined readme.txt

git-svn-id: https://plugins.svn.wordpress.org/recent-contributors-widget/trunk@1003828 b8457f37-d9ea-0310-8a92-e5e31aec5664
Created trunk files from v1.0

git-svn-id: https://plugins.svn.wordpress.org/recent-contributors-widget/trunk@1003829 b8457f37-d9ea-0310-8a92-e5e31aec5664