Update contributing doc to explain how to test CLI and controller images

[cmwylie19]

Describe what should be investigated or refactored

A new contributor who is working on a CLI command was confused as to how to run the new command. We need to update the contributing doc to show how to use npx ts-node src/cli.ts <command>

Also update the document to show how to use pepr:dev to use the latest controller code.

Explain how you could use npm pack to bring in a development cli to a new module.

The package.json had a lot of examples on how to run e2e, unit test, lint.

The pepr-excellent-examples has examples in the README.md on how to use npm pack to bring a development CLI into a Pepr Module.

[cmwylie19]

@soltysh expressed interest in working on this as he dives into Pepr. 🙏