Refactor design system with Radix

[nathanielrindlaub]

https://www.radix-ui.com/

I really like the simplicity and flexibility of this component library, and it's made by Modulz (creators of Stitches, which we're using for styling), so they should play nicely together.

Check out Radix primatives: https://www.radix-ui.com/docs/primitives/overview/introduction

Radix Icons: https://icons.modulz.app/

Radix Colors: https://www.radix-ui.com/colors