edit readme file

git-svn-id: https://plugins.svn.wordpress.org/ink-appointment-booking/trunk@814249 b8457f37-d9ea-0310-8a92-e5e31aec5664
readme file update

git-svn-id: https://plugins.svn.wordpress.org/ink-appointment-booking/trunk@814253 b8457f37-d9ea-0310-8a92-e5e31aec5664