add react-router examples

src/entry.js

@@ -7,3 +7,4 @@ import './examples/react/index';
 // import './examples/redux/one-file';
 // import './examples/redux/separate-files';
 // import './examples/redux/separate-files-redux-actions';
+// import './examples/router';

src/examples/react/index.js

@@ -1,5 +1,5 @@
-import * as React from 'react';
-import * as ReactDOM from 'react-dom';
+import React from 'react';
+import ReactDOM from 'react-dom';
 import {Hello} from './hello';
 
 ReactDOM.render(

src/examples/router/index.js

@@ -0,0 +1,27 @@
+import React from 'react';
+import ReactDOM from 'react-dom';
+import {BrowserRouter, Link, Route} from 'react-router-dom';
+
+const Route1 = () => <h2>Route1</h2>;
+const Route2 = () => <h2>Route2</h2>;
+
+const App = (props) => {
+  console.log('App', props); // eslint-disable-line no-console
+
+  return (
+    <div>
+      <p><Link to="/route1">route1</Link></p>
+      <p><Link to="/route2">route2</Link></p>
+
+      <Route path="/route1" component={Route1} />
+      <Route path="/route2" component={Route2} />
+    </div>
+  );
+};
+
+ReactDOM.render(
+  <BrowserRouter>
+    <Route component={App} />
+  </BrowserRouter>,
+  document.querySelector('#app')
+);