message: docs(ActionBar): use setup
diff: @@ -29,13 +29,17 @@ app.use(ActionBarButton);
  import { Toast } from 'vant';
  export default {
  - methods: {
  - onClickIcon() {
  + setup() {
  + const onClickIcon = () => {
  Toast('Click Icon');
  - },
  - onClickButton() {
  + };
  + const onClickButton = () => {
  Toast('Click Button');
  - },
  + };
  + return {
  + onClickIcon,
  + onClickButton,
  + };
  },
  };
  ```
  