📝 improve transfer doc

components/transfer/demo/basic.md

@@ -76,8 +76,13 @@ class App extends React.Component {
           render={item => item.title}
           disabled={disabled}
         />
-
-        <Switch unCheckedChildren="disabled" checkedChildren="disabled" checked={disabled} onChange={this.handleDisable} />
+        <Switch
+          unCheckedChildren="disabled"
+          checkedChildren="disabled"
+          checked={disabled}
+          onChange={this.handleDisable}
+          style={{ marginTop: 16 }}
+        />
       </div>
     );
   }

components/transfer/index.en-US.md

@@ -9,6 +9,9 @@ Double column transfer choice box.
 
 ## When To Use
 
+- It is a select control essentially which can be use for selecting multiple items.
+- Transfer can display more information for items and take up more space.
+
 Transfer the elements between two columns in an intuitive and efficient way.
 
 One or more elements can be selected from either column, one click on the proper `direction` button, and the transfer is done. The left column is considered the `source` and the right column is considered the `target`. As you can see in the API description, these names are reflected in.

components/transfer/index.zh-CN.md

@@ -10,7 +10,10 @@ title: Transfer
 
 ## 何时使用
 
-用直观的方式在两栏中移动元素，完成选择行为。
+- 需要在多个可选项中进行多选时。
+- 比起 Select 和 TreeSelect，穿梭框占据更大的空间，可以展示可选项的更多信息。
+
+穿梭选择框用直观的方式在两栏中移动元素，完成选择行为。
 
 选择一个或以上的选项后，点击对应的方向键，可以把选中的选项移动到另一栏。
 其中，左边一栏为 `source`，右边一栏为 `target`，API 的设计也反映了这两个概念。