add Kafka setup to Pub/Sub example

[tomkralidis]

Adding based on geopython/pygeoapi#2258

[doublebyte1]

Thanks a lot for adding this! 🥇 I was going to suggest it, when you did the PR on pygeoapi.

Would you mind:

• Moving the pubsub folder inside the top-level docker folder? mv pubsub ../docker
• Renaming the docker folder to something more meaningful like config or pygeoapi? mv pubsub/docker pubsub/pygeoapi

[tomkralidis]

Thanks a lot for adding this! 🥇 I was going to suggest it, when you did the PR on pygeoapi.

Would you mind:

• Moving the pubsub folder inside the top-level docker folder? mv pubsub ../docker
• Renaming the docker folder to something more meaningful like config or pygeoapi? mv pubsub/docker pubsub/pygeoapi

@doublebyte1 PR fixed / updated.

[doublebyte1]

Thanks a lot, I think this example is incredibly valuable.