Update events.md

vuejs/docs@5524819#diff-1c7fe52c3423d851da9fe23f8e3e3a02d86a587d100ccbf423be254570dcdcc4

Author: naokie

src/guide/events.md

@@ -17,7 +17,7 @@
 Vue.createApp({
   data() {
     return {
-      counter: 1
+      counter: 0
     }
   }
 }).mount('#basic-event')