Refresh error boundary docs and examples

[aurorascharff]

What

Refreshes the README and docs site so the first-pass docs explain the modern react-error-boundary workflow more directly.

• add a README quick start with inline fallbackRender, retry/reset, and logging
• add clear “what errors are caught” and “async errors” sections
• refresh the ErrorBoundary source/API comment with compact, current catch rules
• document the React 19 useTransition Action path for async errors
• add a dedicated transition errors docs example

Why

React's error boundary docs still show the class-component primitive, while function-component users often land here for a reusable boundary. The existing docs explain the API, but the React 19 async behavior is easy to miss.

This keeps useErrorBoundary positioned as the manual path for async work outside Actions, while documenting that errors thrown from a function passed to the startTransition function returned by useTransition can be caught by the nearest boundary.

Generated docs, examples, and search artifacts were updated from the refreshed examples and JSDoc.

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Project	Deployment	Actions	Updated (UTC)
react-error-boundary	Ready	Preview	May 25, 2026 12:52am

[bvaughn]

Thanks Aurora! This is such a helpful PR 🙇🏼

[aurorascharff]

Thanks Aurora! This is such a helpful PR 🙇🏼

Pushing some small tweaks and then it should be good!! 🤩

[bvaughn]

Let me know when you're happy with things and I'll merge!

[bvaughn]

(I was hoping that updated the react-lib-tools dep would fix the failing CI job. Unfortunately it didn't. Sorry for the noise. Feel free to force-push over top of my commit if that's more convenient, and I'll debug this in another branch like I should have done to begin with)

[aurorascharff]

@bvaughn Check it out, I'm done tweaking!

[bvaughn]

Looks great 👍🏼 Thank you!

[bvaughn]

Readme updates have been published in react-error-boundary@6.1.2