[Doc] Create a multi-master cluster with slaves

[Kanshiroron]

Hi there,

I'm trying to understand what could be the configuration to have a 3 master nodes cluster, plus multiple decentralized slaves/replicas?

To provide a bit more context about the deployment I'm looking forward to implementing: we currently are running a 3 masters nodes cluster, hosted on Kubernetes and accessible via a load balancer (we currently cannot access a specific node from outside the k8s cluster). I would like to deploy some new LDAP replicas (non-master) on some other Kubernetes clusters for local auth, in order to offload the master cluster. Is that possible? What config should I apply to non-masters replicas?

Thanks for the help and the project!