Create PoC for GitHub Actions

[e-backmark-ericsson]

This is a placeholder for the idea of creating a PoC for integrating CDEvents with GitHub Actions.

One way to showcase it could be according to an “Iteratively expanding CI/CD System”, for example:

• Initially just a GitHub Actions pipeline, with a set of consumers (e.g. deployer, visualizer, DORA calculator, raw event viewer)
• Secondly break out the pipeline execution to a Tekton pipeline, with no change to the consumers
• Thirdly break out test activities from Tekton pipeline to Testkube, with no change to the consumers

/cc @bradmccoydev

[e-backmark-ericsson]

This work is already started in this separate repo: https://github.com/cdevents/github-action

[e-backmark-ericsson]

Closing this issue since will be handled through the repo mentioned above instead