Add support for containerization

[zleyyij]

End result should mount ./cms-data from the outside, and support the OCI container spec (Docker/Podman)
https://discord.com/channels/749314018837135390/1240828670986162247/1247725710408421387

[PipeItToDevNull]

This is based off alpine, the resulting image is 23.7MB.

Example basic usage

cp default.env .env
podman build -t rts-cms .   
podman run --rm -d -v ~/git/rts-cms/:/app/cms-data/ -p 8080:8080 rts-cms

I cannot confirm the webserver is reachable on my mac for some reason

[PipeItToDevNull]

I tested this on RHEL and it works, so this can be merged