Docs: add English language support (#170)

* feat: support lang entry build

* feat: vant support lang switch

* move lang iframe-router to utils & fix router link bug

* add en-US config && add some translation

* chang async. to async_ (support superman cdn)

* add layout translation

* change nav style

* upgrade zan-doc

* fix: doc config

* upgrade zan-doc && remove useless code

* fix changelog generate path

docs/examples-docs/zh-CN/cell-swipe.md

@@ -0,0 +1,57 @@
+<style>
+.van-cell-swipe__left,
+.van-cell-swipe__right {
+    color: #FFFFFF;
+    font-size: 16px;
+    width: 65px;
+    height: 44px;
+    display: inline-block;
+    text-align: center;
+    line-height: 44px;
+}
+.van-cell-swipe__left {
+  background-color: #FF4444;  
+}
+.van-cell-swipe__right {
+  background-color: #84c483;
+}
+</style>
+## CellSwipe 滑动单元格
+
+### 使用指南
+``` javascript
+import { CellSwipe } from 'vant';
+
+Vue.component(CellSwipe.name, CellSwipe);
+```
+
+### 代码演示
+
+#### 基础用法
+
+:::demo 基础用法
+```html
+<van-cell-swipe :right-width="65" :left-width="65">
+  <span slot="left">选择</span>
+  <van-cell-group>
+    <van-cell title="单元格1" value="单元格1内容"></van-cell>
+  </van-cell-group>
+  <span slot="right">删除</span>
+</van-cell-swipe>
+```
+:::
+
+### API
+
+| 参数       | 说明      | 类型       | 默认值       | 可选值       |
+|-----------|-----------|-----------|-------------|-------------|
+| left-width | 左侧滑动区域宽度 | `Number`  | `0` | - |
+| right-width | 右侧滑动区域宽度 | `Number`  | `0` | - |
+
+### Slot
+
+| name       | 描述      |
+|-----------|-----------|
+| - | 自定义显示内容 |
+| left | 左侧滑动内容 |
+| right | 右侧滑动内容 |