feat(template): add hello prop

Author: klarkc

template/client/App.vue

@@ -1,9 +1,15 @@
 <template lang="html">
-  <h1>Hello World!</h1>
+  <h1>{{ hello }}</h1>
 </template>
 
 <script>
 export default {
+  props: {
+    hello: {
+      type: String,
+      default: 'Hello World!',
+    }
+  }
 }
 </script>