This patch provides documentation for 'Provider Network Groups',
aka 'the ability to define provider networks that are applied only to
certain groups'. This allows deployers to configure provider networks
across a heterogeneous environment as opposed to a homogeneous environment.
It also updates the documentation by providing examples of single and
multi-interface deployments.
The docs call out the steps necessary to configure the
openstack_user_config.yml file to configure provider networks
on a per-group basis. Only groups listed under group_binds for a given
provider network will utilize the given vars.
Change-Id: I9611810722283a8a0e4c57e60576bd0c3506eacc
Closes-Bug: 1814686
df43c5119d
