delete readme

git-svn-id: https://plugins.svn.wordpress.org/yuzo-related-post/trunk@883963 b8457f37-d9ea-0310-8a92-e5e31aec5664
upload readme.txt

git-svn-id: https://plugins.svn.wordpress.org/yuzo-related-post/trunk@883965 b8457f37-d9ea-0310-8a92-e5e31aec5664