Move port definition from docker-compose.yml to override file

[cicalese]

In order to be able to disable caddy in environments that use other mechanisms for SSL termination, one needs to be able to prevent the ports from being exposed. Since it is not (yet) possible to remove properties that are defined in docker-compose.yml by overriding, optional properties must be specified in the override file instead.

[vedmaka]

While this workaround of not exposing ports works, it's not ideal since Caddy is still running and consuming resources. I'd suggest using Compose profiles instead to define which services to use

[cicalese]

The work-around I use for that is to change the definition of caddy in the override file:

  caddy:
    image: alpine:latest
    restart: "no" 
    entrypoint: ["echo", "Caddy is disabled"]

It's a terrible hack, but it works for the time being until a better solution is proposed.