More complex verticle configuration examples

[jvpichowski]

Figure out and write samples for more complex verticle configuration JSON serializable records ("deep" configs, optional fields with default values, etc.)

[pklaschka]

Not a part of the documentation. Given the current structure, this most likely currently fits into the examples package in the core. We should have a dedicated, more discoverable samples repo later, but for now, I'm transferring this over to telestion-core.