README Cleanup

Here's an attempt to standardize the README for this repo.

I grabbed a blurb from the product description and applied the standard images, links, and sections.

**Questions:**
1. How should we describe the contents of the `Production Files` directory? What is that file for?
2. Prior to this branch the README claims the hardware is released under the "Open Hardware License". I searched and found many different licenses that are all called "Open Hardware License" colloquially. Which license is correct for this repo? I replaced the license information with the default CC by SA 3.0 for hardware and Beerware for the rest but this needs to be clarified.