docs(zh): translate the currentRoute section of migration to Chinese (#2163)

* docs(zh): translate the currentRoute section of migration to Chinese

* Apply suggestions from code review

---------

Co-authored-by: Jinjiang <zhaojinjiang@me.com>

Author: gophlet

packages/docs/zh/guide/migration/index.md

@@ -113,15 +113,13 @@ router.resolve({
 
 **原因**：Vue Router 不再使用 `path-to-regexp`，而是实现了自己的解析系统，允许路由排序并实现动态路由。由于我们通常在每个项目中只添加一个通配符路由，所以支持 `*` 的特殊语法并没有太大的好处。参数的编码是跨路由的，无一例外，让事情更容易预测。
 
-<!-- TODO: translation -->
+### 现在 `currentRoute` 属性是一个 `ref()`
 
-### The `currentRoute` property is now a `ref()`
+路由器实例上的 [`currentRoute`](https://v3.router.vuejs.org/zh/api/#router-currentroute) 对象的属性在以前可以被直接访问。
 
-Previously the properties of the [`currentRoute`](https://v3.router.vuejs.org/api/#router-currentroute) object on a router instance could be accessed directly.
+从 vue-router v4 开始，路由器实例上的 `currentRoute` 对象的底层类型已被改为 `Ref<RouteLocationNormalizedLoaded>`，其源自 Vue 3 中新引入的[响应式基础](https://cn.vuejs.org/guide/essentials/reactivity-fundamentals.html)。
 
-With the introduction of vue-router v4, the underlying type of the `currentRoute` object on the router instance has changed to `Ref<RouteLocationNormalizedLoaded>`, which comes from the newer [reactivity fundamentals](https://vuejs.org/guide/essentials/reactivity-fundamentals.html) introduced in Vue 3.
-
-While this doesn't change anything if you're reading the route with `useRoute()` or `this.$route`, if you're accessing it directly on the router instance, you will need to access the actual route object via `currentRoute.value`:
+当你使用 `useRoute()` 或 `this.$route` 获取路由信息时这并不会带来任何变化，如果想要直接在路由器实例上访问它，你需要通过 `currentRoute.value` 来访问实际的路由对象：
 
 ```ts
 const { page } = router.currentRoute.query // [!code --]