updated readme with more information about the beta release

git-svn-id: https://plugins.svn.wordpress.org/pro-writer-lite/trunk@1043588 b8457f37-d9ea-0310-8a92-e5e31aec5664
update readme

git-svn-id: https://plugins.svn.wordpress.org/pro-writer-lite/trunk@1043589 b8457f37-d9ea-0310-8a92-e5e31aec5664
changed name to indicate lite

git-svn-id: https://plugins.svn.wordpress.org/pro-writer-lite/trunk@1043592 b8457f37-d9ea-0310-8a92-e5e31aec5664