feat: use twin.macro

[mattrothenberg]

Ignore the branch name. I deviated a lot from my initial strategy 😅

Todo

• Figure out how to style the "example" app without Tailwind (so that we can ensure styles aren't leaking through).
• Figure out how to pass in classes from our categoryColors map, since I don't think these can be applied dynamically at runtime anymore (these also shouldn't have been getting purged before, which is confusing)
• Figure out why headers are so wonky!

Notes

• In order to pass Tailwind classes conditionally, we'll need to use the css prop, which takes an array of strings. Conditionally add/remove strings here that are formatted thusly:

tw`name-of-tailwind-class`

• Classes that are not part of our Tailwind config need to be passed through the regular className prop