* Add caveat that we don't support PG HA in secondaries
* Suggest ensuring the secondary cluster works without Geo first
* Add configuration to disable geo_logcursor on the PG read-replica node
  to prevent it from attempting to configure Rails if you don't have any
  Rails services explicitly enabled. Otherwise, reconfigure could get
  blocked on things like erroring on migrating databases even though you
  never asked to run geo_logcursor on the PG node.
* Add suggestion to run backend Rails services on backend app nodes