Added readme.html in SVN

git-svn-id: https://plugins.svn.wordpress.org/https-domain-alias/trunk@857051 b8457f37-d9ea-0310-8a92-e5e31aec5664
Sync with git

git-svn-id: https://plugins.svn.wordpress.org/https-domain-alias/trunk@860276 b8457f37-d9ea-0310-8a92-e5e31aec5664