Add readme

Status: **Opened for visibility**
Reviewers: @ry5n @jeffkamo 

## Changes
- Added a readme

## Notes
- Not sure if we really need as much detail about the variables file as I've added here. Might be worth dropping that section. Let me know your thoughts.
- Fixes #3 

@jeffkamo Yeah, inline coding the variable name makes more sense. I'll make that change. I'll take a look at rewording that example.