docs: translation tooltip (#2577)

components/tooltip/demo/basic.md

@@ -1,16 +1,24 @@
 ---
 order: 0
-title: 基本
+title: 
+  zh-CN: 基本
+  en-US: Basic
 ---
 
+## zh-CN
+
 最简单的用法。
 
+## en-US 
+
+The simplest usage.
+
 ````jsx
 import { Tooltip } from 'antd';
 
 ReactDOM.render(
-  <Tooltip title="提示文字">
-    <span>鼠标移上来就会出现提示</span>
+  <Tooltip title="prompt text">
+    <span>Text will show when mouse enter.</span>
   </Tooltip>
 , mountNode);
 ````

components/tooltip/demo/placement.md

@@ -1,58 +1,66 @@
 ---
 order: 1
-title: 位置
+title: 
+  zh-CN: 位置
+  en-US: Placement
 ---
 
+## zh-CN
+
 位置有 12 个方向。
 
+## en-US 
+
+The ToolTip has 12 placements choice.
+
 ````jsx
 import { Tooltip } from 'antd';
-const text = <span>提示文字</span>;
+const text = <span>prompt text</span>;
 
 ReactDOM.render(
   <div>
     <div style={{ marginLeft: 60 }}>
       <Tooltip placement="topLeft" title={text}>
-        <a href="#">上左</a>
+        <a href="#">topLeft</a>
       </Tooltip>
       <Tooltip placement="top" title={text}>
-        <a href="#">上边</a>
+        <a href="#">top</a>
       </Tooltip>
       <Tooltip placement="topRight" title={text}>
-        <a href="#">上右</a>
+        <a href="#">topRight</a>
       </Tooltip>
     </div>
     <div style={{ width: 60, float: 'left' }}>
       <Tooltip placement="leftTop" title={text}>
-        <a href="#">左上</a>
+        <a href="#">leftTop</a>
       </Tooltip>
       <Tooltip placement="left" title={text}>
-        <a href="#">左边</a>
+        <a href="#">left</a>
       </Tooltip>
       <Tooltip placement="leftBottom" title={text}>
-        <a href="#">左下</a>
+        <a href="#">leftBottom</a>
       </Tooltip>
     </div>
     <div style={{ width: 60, marginLeft: 270 }}>
       <Tooltip placement="rightTop" title={text}>
-        <a href="#">右上</a>
+        <a href="#">rightTop</a>
       </Tooltip>
       <Tooltip placement="right" title={text}>
-        <a href="#">右边</a>
+        <a href="#">right</a>
       </Tooltip>
       <Tooltip placement="rightBottom" title={text}>
-        <a href="#">右下</a>
+        <a href="#">rightBottom</a>
       </Tooltip>
     </div>
     <div style={{ marginLeft: 60, clear: 'both' }}>
       <Tooltip placement="bottomLeft" title={text}>
-        <a href="#">下左</a>
+        <a href="#">bottomLeft</a>
       </Tooltip>
       <Tooltip placement="bottom" title={text}>
-        <a href="#">下边</a>
+        <a href="#">bottom</a>
       </Tooltip>
       <Tooltip placement="bottomRight" title={text}>
-        <a href="#">下右</a>
+        <a href="#">bottomRight</a>
       </Tooltip>
     </div>
   </div>

components/tooltip/index.en-US.md

@@ -0,0 +1,23 @@
+---
+category: Components
+type: Views
+title: Tooltip
+---
+
+A simple text popup tip.
+
+## When To Use
+
+- The tip shows while mouse enter, and hides while mouse leave, the ToolTip doesn't support complex text and operation.  
+
+- It can provide a explain of `button/text/opration`, that can cover the usage of the default system `title`. 
+
+## API
+
+| Property      | Description                                     | Type       | Default |
+|-----------|------------------------------------------|------------|--------|
+| placement | to set the position, which can be one of `top` `left` `right` `bottom` `topLeft` `topRight` `bottomLeft` `bottomRight` `leftTop` `leftBottom` `rightTop` `rightBottom` | string     | top    |
+| title     | prompt text                                 | string/React.Element | -     |
+| getTooltipContainer | to set the container of the tip, while the default is to create a `div` element in `body` | Function(triggerNode) | () => document.body |
+
+You can visit https://github.com/react-component/tooltip for more API.