Add config options to streamline with k8s standards

[hmuendel]

Many K8s inegrations are controlled via annotations on the resources
e.g Prometheus discovery or load balancer behavior, making them
configurable adds more flexibility to the deployment.

Also the fields in the TLS secret are by default tls.crt and tls.key
making this configurable increases integration with tools like
cert-manager

[bd-skatzman]

This is similar, in some respect, to #74. A more flexible configuration model to enable operators to define annotations for external tools or people.