message: docs(NumberKeyboard): use composition api
diff: @@ -25,21 +25,24 @@ app.use(NumberKeyboard);
  ```
  ```js
  +import { ref } from 'vue';
  import { Toast } from 'vant';
  export default {
  - data() {
  - return {
  - show: true,
  - };
  - },
  - methods: {
  - onInput(value) {
  + setup() {
  + const show = ref(true);
  + const onInput = (value) => {
  Toast(value);
  - },
  - onDelete() {
  + };
  + const onDelete = () => {
  Toast('delete');
  - },
  + };
  +
  + return {
  + show,
  + onInput,
  + onDelete,
  + };
  },
  };
  ```
  @@ -125,11 +128,15 @@ Use `title` prop to set keyboard title.
  ```
  ```js
  +import { ref } from 'vue';
  +
  export default {
  - data() {
  + setup() {
  + const show = ref(true);
  + const value = ref('');
  return {
  - show: false,
  - value: '',
  + show,
  + value,
  };
  },
  };
  