CI: Makefile commands for MongoDB container set up

[joshua-mo-143]

• Creates a Makefile with commands to manage set-up and teardown of a MongoDB docker container.
• Update main README.md to account for database connection information

At some point I would like to introduce a fully-working Docker Compose file, but I've been having some issues trying to get the containers to talk to each other so this will have to do for now.

The reason why this PR has been opened is that as mentioned in #47 if we want to continue this project to completion, we should make it as easy as possible for new contributors to start contributing.

[joshua-mo-143]

Closed because this exists and is already in progress: https://github.com/SHIV5T3R/CO-DE/pull/28