readme changed

git-svn-id: https://plugins.svn.wordpress.org/oi-yamaps/trunk@991502 b8457f37-d9ea-0310-8a92-e5e31aec5664
version changed to 2.2

git-svn-id: https://plugins.svn.wordpress.org/oi-yamaps/trunk@991515 b8457f37-d9ea-0310-8a92-e5e31aec5664