Updated the README file
Updated the README file

Added the line about how HOUND behaves when it has nothing to check ...
For reference [see this](https://github.com/houndci/hound/issues/1692#issuecomment-475970034)
Hope this will help others !! 😇
thoughtbot/hound,thoughtbot/hound,thoughtbot/hound,houndci/hound,houndci/hound,thoughtbot/hound,houndci/hound,houndci/hound