Add GitHub code annotations on typechecking error

[aabounegm]

Annotations in GitHub Actions look like so:

It would be useful if this action can provide annotations to help spot the error directly in the code review page of a pull request. This can be done with the annotations-action, which requires input in the following format:

[
  {
    "file": "path/to/file.rzk.md",
    "line": 5,
    "title": "Title of the error message",
    "message": "Details about the error message",
    "annotation_level": "failure"
  }
]

This probably requires Rzk itself to support JSON output format.
More details about annotations can also be found in this blog post