https://pagure.io/centos-infra/issue/1558

Based on discussion with @shaunm , we can now deploy new infra/role for docs.centos.org and also redirect A/AAAA record to new vhost.
Then modify also role to have docs.stg.centos.org start pulling from `staging` branch from https://gitlab.com/CentOS/docs/docs.centos.org (not existing for the moment but easy to add once branched)