[Doc] add some english documents (#220)

* [bugfix] Checkbox border render error in weixin browser

* [bugfix] TreeSelect dependency path error

* [bugfix] Swipe should clear autoplay timer when destroyed

docs/examples-docs/en-US/uploader.md

@@ -0,0 +1,57 @@
+<script>
+export default {
+  methods: {
+    logContent(file) {
+      console.log(file)
+    }
+  }
+};  
+</script>
+
+## Uploader
+
+### Install
+``` javascript
+import { Uploader } from 'vant';
+
+Vue.component(Uploader.name, Uploader);
+```
+
+### Usage
+
+#### Basic Usage
+
+:::demo Basic Usage
+```html
+<div class="uploader-container">
+  <van-uploader :after-read="logContent">
+    <van-icon name="photograph"></van-icon>
+  </van-uploader>
+</div>
+```
+
+```javascript
+export default {
+  methods: {
+    logContent(file) {
+      console.log(file)
+    }
+  }
+};  
+```
+:::
+
+### API
+
+| Attribute | Description | Type | Default | Accepted Values |
+|-----------|-----------|-----------|-------------|-------------|
+| resultType | 读取文件的方式，以base64的方式读取；以文本的方式读取 | `String` | `dataUrl` | `text` |
+| disable | 是否禁用上传,在图片上传期间设置为true，禁止用户点击此组件上传图片 | `Boolean` | `false` | - |
+| beforeRead | 读文件之前的钩子，参数为选择的文件，若返回 false 则停止读取文件 | `Function` | - | - |
+| afterRead | 文件读完之后回调此函数，参数为 { file:'选择的文件',content:'读的内容' } | `Function` | - | - |
+
+### Slot
+
+| name | Description |
+|-----------|-----------|
+| - | 自定义上传显示图标 |