feat: Add Docker image

[sevir]

This Dockerfile allow to create a docker image for running kickstart without download the binary and working with the same binary in Windows, Linux and OSX

An example for running using docker:
docker run -it ghcr.io/sevir/kickstart:latest --help

I've pushed the image into the Github Container Registry, but works with any docker image

[sevir]

debian12 distroless does not have git, I don't see that is a requirement for kickstart, I changed for debian 12 slim with git

[Keats]

Does this need to be in the repository?

[sevir]

Normally the image build process includes to build the binary and copy the binary into the final image. Users can write a Dockerfile that downloads the last release binary but is not associated to the specific version, and is less standard.

So, yes, normally Dockerfile is associated with the source in the repository

[Keats]

I think to do that well, it needs to be hooked in GH actions like https://github.com/getzola/zola/blob/master/.github/workflows/release.yml#L135 so it publishes the docker image automatically on new tags. I will never remember to publish a new version otherwise. I think for the Dockerfile I would rather have something where I can specify the version like in https://github.com/getzola/zola/blob/master/Dockerfile