fix typos in guide introduction

Author: chrisvfritz

src/guide/index.md

@@ -284,7 +284,7 @@ Now we can pass the todo into each repeated component using `v-bind`:
 var app7 = new Vue({
   el: '#app-7',
   data: {
-  todos: [{ /* ... */}]
+    todos: [/* ... */]
   }
 })
 ```