Update README and Makefile.

[DFurnes]

What's this PR do?

This pull request updates this repository's README file.

How should this be reviewed?

I'll drop some notes with context on changes in the diff!

Any background context you want to provide?

🍃

Relevant tickets

References Pivotal #179704485.

Checklist

• [ ] This PR has been added to the relevant Pivotal card.