fix(Events): escape @ in code tags (#1455)

* fix(Events): escape at sign in code tags

* Update tip example to v-on instead of @

Author: naeramarth7

src/v2/guide/events.md

@@ -194,7 +194,7 @@ To address this problem, Vue provides **event modifiers** for `v-on`. Recall tha
 <div v-on:click.self="doThat">...</div>
 ```
 
-<p class="tip">Order matters when using modifiers because the relevant code is generated in the same order. Therefore using `@click.prevent.self` will prevent **all clicks** while `@click.self.prevent` will only prevent clicks on the element itself.</p>
+<p class="tip">Order matters when using modifiers because the relevant code is generated in the same order. Therefore using `v-on:click.prevent.self` will prevent **all clicks** while `v-on:click.self.prevent` will only prevent clicks on the element itself.</p>
 
 > New in 2.1.4+