update of readme file

git-svn-id: https://plugins.svn.wordpress.org/s-crib-otp-authentication/trunk@848335 b8457f37-d9ea-0310-8a92-e5e31aec5664
update of readme file

git-svn-id: https://plugins.svn.wordpress.org/s-crib-otp-authentication/trunk@848340 b8457f37-d9ea-0310-8a92-e5e31aec5664