[Suggestion]: Make clear why Ref was used in the third solution

Summary

The solution for the third challenge, "Fix debouncing," does not require a Ref. Moving the let timeoutID; to the top inside the DebouncedButton component will fix the debouncing. Either point this out in the explanation or make it re-render so the solution requires Ref.

Page

https://react.dev/learn/referencing-values-with-refs

Details

Since code example does not use State, there's no re-rendering, and so there's no need to use Ref to remember anything across re-renders. The page mentions that Refs are not used often; although future-proof, I think the example should only use Ref when necessary.

从“Referencing Values with Refs”页面开始，检查第三个挑战“Fix debouncing”，包括其解释和解决方案。完成的标准是文档解释为什么使用 Ref，或者修改示例，使重新渲染成为必须使用 Ref 的原因；验证渲染后的页面和挑战的措辞。