Readme update

git-svn-id: https://plugins.svn.wordpress.org/sermon-manager-import/trunk@839266 b8457f37-d9ea-0310-8a92-e5e31aec5664
Tagging version 0.2.3

git-svn-id: https://plugins.svn.wordpress.org/sermon-manager-import/trunk@839267 b8457f37-d9ea-0310-8a92-e5e31aec5664