break-out ROSA w/ HCP documentation

Currently, the ROSA official documentation consists of both ROSA classic and ROSA (w/ HCP) content.

To reduce confusion, we will break-out or split off the ROSA (w/ HCP) content to its own book in docs.redhat.com. 

As part of this, the HCP-related content from the prior ROSA (classic architecture) will be removed to ensure both 'books' are separated.