Implement Code Coverage

Attempt to implement Code coverage that is automatically run on CI builds

### Acceptance Criteria
GIVEN I am a Free Code Camp developer
WHEN I run `npm run test` on the CLI
THEN the `coverage` folder will be created
AND all the unit tests will be run
AND I will see the code coverage report

### Guidance
- [How to Generate a Code Coverage Report with CodeCov and GitHub Actions](https://www.freecodecamp.org/news/how-to-generate-code-coverage-report-with-codecov-and-github-actions/)
- Use the legacy website [package.json](https://github.com/FCCColumbus/fcc-columbus/blob/master/package.json) as an example of how it was working. Making it work like this is fine.
- You might need to create some unit tests!

Start with the repository's package.json and run npm run test to inspect the current test workflow. Compare it with the legacy website package.json and the linked CodeCov/GitHub Actions guidance; done means the coverage folder and report are produced while all unit tests run in the CLI and CI.

Written by the indexing model from the issue text.