CLI Improvements - submit code without Git + bugfixes

The CLI now exposes a command called codecrafters submit:

This does the same as the Git equivalent (git add, commit and push), but it’s slightly faster and less keystrokes!

With this, you can now run tests and move through stages without touching the git command at all.

In this update we’ve also fixed two long-standing bugs with the CLI:

If you’re on an old CLI version, you’ll be prompted to upgrade soon. Update instructions can be found here: How do I update the CLI? - CodeCrafters