BE: Setup Mongo Database

[jessdesr]

• Connect to a database technology on start of your application (please only select one technology, try to choose something that is a good fit for your project if possible, or something you are comfortable with using)

• Use MongoDB Atlas

• Discuss with backend task owner: build a very basic user model that will be needed for login / signup of the application

• For MongoDB, we recommend using Mongoose for Node.js.

• Because you'll be using a cloud service, the environment variables must not be uploading. Add .env to gitignore file so it will no longer be tracked.