Add Docker publish action

[BSchilperoort]

In STEMMUS_SCOPE a new docker image is built and pushed by Github Actions upon a new release.

We should add this for this repo as well. However, there is one complication: I have used the model tag as the container tag (I.e. stemmus_scope-grpc4bmi:1.5.0 uses the stemmus_scope:1.5.0 container. The workflow uses the repository's tag/release version, which would be stemmus_scope-grpc4bmi:0.4.0.

[SarahAlidoost]

With actions/github-script , it is possible to fetch the release tag from the other repository, see some related examples here. However, stemmus_scope-grpc4bmi:0.4.0 is fine. The version of the model e.g. 1.6.1 is specified in the Dockerfile. Since Docker installs latest pystemmusscope, it would be better if the tag aligns with the pystemmusscope release, rather than stemmus_scope itself.

[SarahAlidoost]

• add the GA action
• add documentation