refactor(example): use 'v-role" to illustrate its use

Author: mblarsen

example/src/pages/Home.vue

@@ -1,6 +1,6 @@
 <template>
  <div>
- <section v-can:admin>
+ <section v-role:admin>
  <h2>Admin commands</h2>
  <p>
  Here would be some admin commands. Note: `vue-browser-acl` is only a