Add readme

*Work in progress. Will be added to as work progresses*.

Add readme that outlines installation, usage, and license, and links to expanded/supporting docs.

Status: **In progress**

Reviewers: @jeffkamo @kpeatt 
Ticket: When ready, fixes #27 
Linked PRs: whichever fixes #29 

## Changes
- Add readme
- Link to supporting docs

## How to test-drive this PR
- N/A