Add 'use client' to react components

[suhaibmujahid]

This will allow importing the components in Next.js (App Router) without the need to wrap the components to create a client component boundary.

This could be added in addition or replacing import 'client-only':

headlessui/packages/@headlessui-react/src/index.ts

Line 1 in 1469b85

import 'client-only'

Related:

• Supports usage in React server components #2263 (comment)
• Add client-only to mark everything as client components #1981 (comment)
• headless ui support with react server components #1300 (comment)