Publicize undocumented components

[rezrah]

primer.style/brand documentation currently shows a handful of cherry-picked UI patterns, rather than the entire inventory of components available through the npm package.

List of undocumented components at time of issue creation:

• Button
• InlineLink
• Accordion
• Link
• ThemeProvider (merged into theming, but could benefit from separate docs for the React component API)
• ExpandableArrow
• hooks
  • useKeyboardEscape
  • useOnClickOutside
  • useIsomorphicEffect
• Page layout examples
  • Kitchen sink

Proposal

• Review components listed above and decide which ones (if any) warrant separate doc pages.
• Publish new doc pages

Why do this?

• Increase adoption of Primer Brand library by accurately documenting existing inventory.
• Storybook is being used as a source of truth and shopfront right now as docs examples are sparse.

Questions

• Should hooks be documented?
• Categorisation of components and impact on discoverability.. should Buttons and InlineLink go under Call to Actions or Components?