Added MongoDB Atlas service

| React, website, MongoDB

Again, following the tutorials wasn't too bad: How to Integrate MongoDB Into Your Next.js App

I had to learn a bit about NoSQL, but that was one of the goals. I chose to do server side rendering for speed.

And, really the whole exercise was to try it out. It really is overkill for my current application, but I wanted to know how to do it for when I really need to do it.