delete trunk readme

git-svn-id: https://plugins.svn.wordpress.org/sharedom/trunk@879227 b8457f37-d9ea-0310-8a92-e5e31aec5664
add trunk readme

git-svn-id: https://plugins.svn.wordpress.org/sharedom/trunk@879229 b8457f37-d9ea-0310-8a92-e5e31aec5664