[Suggestion]: Cap the height of the artificially-slow example output (useDeferredValue / useTransition)

Summary

When you view the example's rendered output in full, the SlowList/SlowPost demos expand into hundreds of identical rows, which is more than anyone needs to scroll through. The output height should be capped (e.g. max-height + scroll) while keeping the item counts that create the intentional slowdown.

Page

https://react.dev/reference/react/useDeferredValue
https://react.dev/reference/react/useTransition

Details

The point of these demos is felt within the first few rows — you just need to see the list "lag behind" the input. But the rendered output shows the full list, so viewing it expands the example to hundreds of identical "Text:" rows and pushes the rest of the docs far down. The number of rows differs across pages (250 / 500 / 50), so the problem shows up unevenly.

从 useDeferredValue 和 useTransition 参考页面中的示例开始，检查 SlowList 和 SlowPost 如何渲染其输出。通过滚动限制可见输出的高度，同时保留现有的项目数量和有意设置的减速效果，然后验证这两个页面不再过度扩展。