Update Introduction.md

Author: ryanflorence

docs/Introduction.md

@@ -189,15 +189,18 @@ render((
     <Route path="/" component={App}>
       <Route path="about" component={About} />
       <Route path="inbox" component={Inbox}>
-        {/* Add the route, nested where we want the UI to nest */}
+        {/* add some nested routes where we want the UI to nest */}
+        {/* render the stats page when at `/inbox` */}
+        <IndexRoute component={InboxStats}/>
+        {/* render the message component at /inbox/messages/123 */}
         <Route path="messages/:id" component={Message} />
       </Route>
     </Route>
   </Router>
 ), document.body)
 ```
 
-Now visits to URLs like `inbox/messages/Jkei3c32` will match the new route and build this:
+Now visits to URLs like `inbox/messages/Jkei3c32` will match the new route and build this for you:
 
 ```
 <App>
@@ -207,6 +210,17 @@ Now visits to URLs like `inbox/messages/Jkei3c32` will match the new route and b
 </App>
 ```
 
+And visits to `/inbox` will build this:
+
+```
+<App>
+  <Inbox>
+    <InboxStats />
+  </Inbox>
+</App>
+```
+
+
 ### Getting URL Parameters
 
 We're going to need to know something about the message in order to fetch it from the server. Route components get some useful properties injected into them when you render, particularly the parameters from the dynamic segment of your path. In our case, `:id`.