docs: consider an optional React refresher on the MDX and React page

### Have you read the Contributing Guidelines on issues?

- [x] I have read the [Contributing Guidelines on issues](https://github.com/facebook/docusaurus/blob/main/CONTRIBUTING.md#issues).

### Description

The “MDX and React” guide introduces JSX and React components and already links to external MDX learning material near the top of the page.

Would a short, clearly optional React refresher help readers who can use Docusaurus but want to strengthen the render/state/effects model behind the examples?

Suggested resource: [React interview preparation path](https://frontendatlas.com/guides/framework-prep/react-prep-path)

The public guide covers components, JSX, props and state, then moves into hooks/effects, state ownership, rendering behavior, testing, and performance trade-offs. If this kind of third-party companion is in scope, I would keep the documentation change to one optional sentence and only prepare a PR after maintainer confirmation.

Disclosure: I created and maintain FrontendAtlas and am affiliated with the linked resource. The guide is publicly readable without signing in; the broader platform includes optional paid features. No paid, affiliate, reciprocal, or special link treatment is requested. If interview-oriented preparation does not fit Docusaurus documentation, please close this request.

### Self-service

- [ ] I'd be willing to address this documentation request myself.