Write Node Challenge Solution for W4, mailing list challenge

Which module(s) and week(s) does this change affect? Module(s): Node Week(s): 4

What is the work that needs to be done?

[x] Write an example solution for https://github.com/CodeYourFuture/Node-Coursework-Week4
[x] Use the coursework template, do not fork from the coursework
[x] Make the repo private
[x] Add tests
[x] Add a GitHub action to run tests on PR
[x] Add the Mentors top level team as Read role
[x] Add each Mentor regional admin team as Admin role
[x] Protect the main branch
[x] Update the Table of Contents to complete this ticket

Why is this work important to do?

Useful guide for mentors (and for learners) for code review

Additional context

Week 4 doesn't yet "exist" on the syllabus.codeyourfuture.io website. You might want to create another ticket for that.
Next class to do Node is NW5 7/1/23

Who might need to know about this change?

CodeYourFuture / syllabus