Move parts of HACKING to README, along with how to add rules, how to version. This is the first pass at the README, it's expected to continue to grow Change-Id: I2dcbc0ae8a65f67c64cf406ac2efc6ee4a305ee4 Reviewed-on: https://review.openstack.org/30942 Reviewed-by: Mark McLoughlin <markmc@redhat.com> Reviewed-by: Sean Dague <sean@dague.net> Approved: Mark McLoughlin <markmc@redhat.com> Tested-by: Jenkins