Add package job to GitHub CI to build and push docker image to GitHub Container Registry

[KoalaGeo]

This PR adds a GitHub workflow to build a Docker image and push to the GitHub Container registry.

See https://github.com/KoalaGeo/tippecanoe/pkgs/container/tippecanoe

The job will run on completion of the test job (image will be tagged latest) and all on an new release (image will be tagged with the release version).

To test docker run -v ./tests/ne_110m_populated_places:/data ghcr.io/koalageo/tippecanoe:latest tippecanoe -zg -o /data/out.pmtiles --drop-densest-as-needed /data/in.json

When the job runs on the felt org, the image will be pushed to ghcr.io/felt/tippecanoe

[zstadler]

@e-n-f, @ChrisLoer, @dnomadb, @arredond

Please review this PR.
Automatic publishing of a felt/tippecanoe docker image would be a great addition to Tippecanoe!

IMO, there are too may docker images floating around. Many of them are really out-dated. Docker Hub, for example, has 101 of them. The best matches are 5 and 4 years-old...

[spwoodcock]

Dup of #282
The workflow in #282 builds multi-arch images 😄