[Doc] props title

packages/area/en-US.md

@@ -37,7 +37,7 @@ Set `columns-num` with 2, you'll have a 2 level picker.
 ```
 
 
-### API
+### Props
 
 | Attribute | Description | Type | Default |
 |------|------|------|------|
@@ -51,7 +51,7 @@ Set `columns-num` with 2, you'll have a 2 level picker.
 | confirm-button-text | Text of confirm button | `String` | `Confirm` |
 | cancel-button-text | Text of cancel button | `String` | `Cancel` |
 
-### Event
+### Events
 
 | Event | Description | Arguments |
 |------|------|------|

packages/area/zh-CN.md

@@ -35,7 +35,7 @@ Vue.use(Area);
 <van-area :area-list="areaList" :columns-num="2" title="标题" />
 ```
 
-### API
+### Props
 
 | 参数 | 说明 | 类型 | 默认值 | 版本 |
 |------|------|------|------|------|
@@ -49,7 +49,7 @@ Vue.use(Area);
 | confirm-button-text | 确认按钮文字 | `String` | `确认` | 1.5.3 |
 | cancel-button-text | 取消按钮文字 | `String` | `取消` | 1.5.3 |
 
-### Event
+### Events
 
 | 事件 | 说明 | 回调参数 |
 | --- | --- | --- |