set up CI/CD pipeline for tool discovery

[proycon]

Use cases for the CI/CD pipeline were requested by @mmisworking , to be set up in February. This is one of them.

• The container should automatically be built, stored in container registry, and deployed on production k8s cluster after each release of https://github.com/CLARIAH/tool-discovery
• The container should automatically be built, stored in container registry, and deployed on development k8s cluster after each commit (or manual trigger?)

[proycon]

@mmisworking Can you set up links to the available documentation on your end for all of this and make sure they're linked from this clariah-plus repo (if not in it) so we can find stuff?