feat: prototype building dynamic react route

lib/core/index.js

@@ -1,10 +1,34 @@
 import React from 'react';
 import {render} from 'react-dom';
-import theme from '@theme';
+import {BrowserRouter, Route, Switch} from 'react-router-dom';
+import Hello from '@theme/hello';
+import Layout from '@theme/layout';
 
 class App extends React.Component {
   render() {
-    return <div>Hello world! {theme()} </div>;
+    // https://reacttraining.com/react-router/web/example/route-config
+    const routes = [
+      {
+        path: '/',
+        component: Hello
+      },
+      {
+        path: '/layout',
+        component: Layout
+      }
+    ];
+
+    return (
+      <BrowserRouter>
+        <div>
+          <Switch>
+            {routes.map(({path, component}) => (
+              <Route key={path} exact path={path} component={component} />
+            ))}
+          </Switch>
+        </div>
+      </BrowserRouter>
+    );
   }
 }
 render(<App />, document.getElementById('app'));