Bug 2073417

Description of problem:

CephDashboardNetwork has been introduced in OSP 16.2.2 as result of the following Bugzilla:
[RFE]: allow for the deployment of RHCS dashboard on any composable network"

Even if this new feature is included in the Release Notes of OSP 16.2 (Section: 3.3.3. Enhancements) at: https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/16.2/html/release_notes/chap-release_notes

No description related to "Deploying Ceph DashboardCephDashboardNetwork" has been integrated/added in the official Red Hat OpenStack document available at:
https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/16.2/html/deploying_an_overcloud_with_containerized_red_hat_ceph/adding-ceph-dashboard

Version-Release number of selected component (if applicable):
Red Hat OpenStack 16.2.2

Expected results:
- Official document updated and aligned to the new feature delivered in OSP 16.2.2.
- Limitations related to this feature documented (e.g.: see the four customer questions in the additional info)

Additional info:
These are also some Customer open points connected to this feature undocumented:

- can we set the external network as the CephDashboardNetwork?
- can we reserve a specific VIP on the new network (as we do on the ctlplane network) or will it use the default external VIP?
- can we change the Ceph dashboard network *for an already deployed overcloud* so that we can move the dashboard away from the ctlplane network (single-armed GbE NICs) and place it on the external network (2x LACP bonded 10GbE NICs, also hosting the default route for the controllers)?