delete old readme

git-svn-id: https://plugins.svn.wordpress.org/socializer/trunk@821101 b8457f37-d9ea-0310-8a92-e5e31aec5664
upload new readme

git-svn-id: https://plugins.svn.wordpress.org/socializer/trunk@821103 b8457f37-d9ea-0310-8a92-e5e31aec5664