Add GitHub Super-Linter actions workflow

[anthonyfok]

Similar to OpenDRR/opendrr-api#178, add a GitHub workflow that uses the Super-Linter Action.

• Test on a personal fork (e.g. https://github.com/anthonyfok/model-factory) first
• Fix all linter warnings/errors on the personal fork
• Open a pull request in this repo.

For reference:

• Add GitHub Super-Linter workflow opendrr-api#178