Merge pull request #5 from Binaryify/patch-2

add middleware chinese document

cn/api/pages-middleware.md

@@ -5,4 +5,32 @@ description: Documentation is coming soon.
 
 # middleware 属性
 
-> 文档未完待续!
+类型: String 或 Array
+Items: String 
+
+在应用中的特定页面设置中间件 
+
+例子: 
+`pages/secret.vue` 
+```vue
+<template>
+  <h1>Secret page</h1>
+</template>
+
+<script>
+export default {
+  middleware: 'authenticated'
+}
+</script>
+```
+`middleware/authenticated.js` 
+```javascript
+export default function ({ store, redirect }) {
+  // If the user is not authenticated
+  if (!store.state.authenticated) {
+    return redirect('/login')
+  }
+}
+``` 
+
+想了解更多关于使用中间件的信息，请移步 [中间件指引](https://nuxtjs.org/guide/routing#middleware)。