nightly-2024-04-14: chore(debugger): Docs (#4145)

# Description

Adds documentation for the Noir debugger.

## Problem

Part of #3015.

## Summary

Adds quickstart, how to's and reference pages to Noir's docsite covering
both the VS Code and REPL debuggers.

## Documentation

Check one:
- [ ] No documentation needed.
- [x] Documentation included in this PR.
- [ ] **[Exceptional Case]** Documentation to be submitted in a separate
PR.

# PR Checklist\*

- [x] I have tested the changes locally.
- [x] I have formatted the changes with [Prettier](https://prettier.io/)
and/or `cargo fmt` on default settings.