Add contributing information to a `CONTRIBUTING.md` file - 2

Description of development task:

As an open source contributor I want to have a CONTRIBUTING.md file so that I know the correct process for developing additions to the MTTL.

Acceptance Criteria:

• Given I am viewing the root of the git repository Then I should see a CONTRIBUTING.md file in the list And When I click on this file Then I am presented with markdown describing the items in Note 1.

Notes

1. Process/information needed for submitting a Merge Request, Location to find features needing to be worked, Instructions for running the code locally, and Styling and/or coding standards.
2. Currently there are some basic instructions on submitting issues, but nothing for actually contributing to the project in an open-source-like fashion. I can manually run through the code, and create an MR, but I am not sure of where to find the items in Note 1.
3. Normally Open Source projects have a CONTRIBUTING.md file in their root directory that shows this information: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md