Update index.zh-CN.md (alibaba#2242)

Author: KuaiYu95

packages/hooks/src/useDocumentVisibility/index.zh-CN.md

@@ -23,4 +23,4 @@ const documentVisibility = useDocumentVisibility();
 
 | 参数               | 说明                                 | 类型                                               |
 | ------------------ | ------------------------------------ | -------------------------------------------------- |
-| documentVisibility | 判断 document 是否在是否处于可见状态 | `visible`\| `hidden` \| `prerender` \| `undefined` |
+| documentVisibility | 判断 document 是否处于可见状态 | `visible`\| `hidden` \| `prerender` \| `undefined` |