build: Add docker container option

[rare-magma]

Containerizing mqttui makes it easier to use without installing it.

The container can then be used like this:

docker run --rm --interactive --tty localhost/mqttui

The docker image could be hosted on ghcr.io and its build automated via github action:
https://docs.github.com/en/actions/publishing-packages/publishing-docker-images

[EdJoPaTo]

Hey! Sorry for the delay, saw this and then forgot about it as it was marked as read.

Thank you for bringing up the topic! I have thought about it but never added it to mqttui so far. So discussing this with others is definitely something great.

I think the big question here is, is it really worth it? mqttui is packaged in for example Alpine so it's relatively quick to use if from there in a container:

podman run --interactive --tty --rm docker.io/library/alpine:edge sh -c 'apk add mqttui && exec mqttui'

Also, my Rust template has a Dockerfile too (and a GitHub Actions workflow publishing it to the ghcr) so I would go with something inspired by that. (Or do you see improvements over there?)

[rare-magma]

hey @EdJoPaTo I hadn't thought about using alpine and installing mqttui just before using it, that is a simpler alternative that will lessen the maintenance burden in the project. Perhaps I could change the PR to just add the podman / docker run example to the readme then?

[EdJoPaTo]

Not sure what the most helpful comment there would be. Like my short approach always redownloads the package again and again. So not sure what I would like to recommend there.