Geo: Clear up documented use of geo_secondary_role
The latest recommendation for the use of the geo_secondary_role is to use it only on single node instances, this is because it can enable/disable a lot of services that in a HA setup might not be desired. At the moment however our documentation lists the use of the geo_secondary_role in several places which can easily confuse if it should be used or not. We should update our documentation to be clearer on when it should be used.
Some uses I've found where we talk about the role in our HA setup guides.
Configuring Patroni cluster for the tracking PostgreSQL database
Configure the main read-only replica PostgreSQL database on the secondary node
Configure the frontend application servers on the secondary node
Configuring Patroni cluster for the tracking PostgreSQL database