update code style

components/breadcrumb/demo/router.md

@@ -8,11 +8,10 @@ title: 路由
 
 ````jsx
 const ReactRouter = require('react-router');
-let { Router, Route, Link, hashHistory } = ReactRouter;
+const { Router, Route, Link, hashHistory } = ReactRouter;
 import { Breadcrumb } from 'antd';
 
-function Apps() {
-  return (
+const Apps = () => (
   <ul className="app-list">
     <li>
       <Link to="/apps/1">应用1</Link>：<Link to="/apps/1/detail">详情</Link>
@@ -21,18 +20,17 @@ function Apps() {
       <Link to="/apps/2">应用2</Link>：<Link to="/apps/2/detail">详情</Link>
     </li>
   </ul>
-  );
-}
+);
 
-function Home(props) {
-  return (
+const Home = (props) => (
   <div>
     <div className="demo-nav">
       <Link to="/">首页</Link>
       <Link to="/apps">应用列表</Link>
     </div>
     {props.children || 'Home'}
-      <div style={{
+    <div
+      style={{
         marginBottom: 15,
         marginTop: 15,
         paddingBottom: 15,
@@ -43,8 +41,7 @@ function Home(props) {
     </div>
     <Breadcrumb {...props} />
   </div>
-  );
-}
+);
 
 ReactDOM.render(
   <Router history={hashHistory}>