Prop documentation generation

[siddharthkp]

There's a lot of plumbing in place to get types for component props to show up on in the docs

Right now we have 2 approaches:

1. Manually add a table of props with markdown. (example)
2. Use react-docgen-typescript to pull types out of component files and render them in the docs (source, example)

Both of these have their cons:

1. Manual documentation needs to be kept up to date by collating types from multiple files. Consistency between pages is extra effort.
2. Documentation generated through docgen¹² isn't super reliable and needs to be manually verified.

We need to figure out our long term strategy:

1. Use types generated by typescript and use that to show in documentation, tools that can help: typedoc | ts-morph. Needs experimentation with compound components.
2. If we don't like what we see, we can fallback on hand crafted data for docs ✨ by choosing what to copy from the generated type definitions

All that to say, we needs more exploration.

Footnotes

1. https://github.com/primer/react/issues/1419 ↩

2. https://github.com/primer/react/pull/1425 ↩