message: docs(PasswordInput): use composition api
diff: @@ -33,11 +33,16 @@ app.use(NumberKeyboard);
  ```
  ```js
  +import { ref } from 'vue';
  +
  export default {
  - data() {
  + setup() {
  + const value = ref('123');
  + const showKeyboard = ref(true);
  +
  return {
  - value: '123',
  - showKeyboard: true,
  + value,
  + showKeyboard,
  };
  },
  };
  @@ -96,22 +101,27 @@ Use `info` to set info message, use `error-info` prop to set error message.
  ```
  ```js
  +import { ref, watch } from 'vue';
  +
  export default {
  - data() {
  - return {
  - value: '123',
  - errorInfo: '',
  - showKeyboard: true,
  - };
  - },
  - watch: {
  - value(value) {
  - if (value.length === 6 && value !== '123456') {
  - this.errorInfo = 'Password Mistake';
  + setup() {
  + const value = ref('123');
  + const errorInfo = ref('');
  + const showKeyboard = ref(true);
  +
  + watch(value, (newVal) => {
  + if (newVal.length === 6 && newVal !== '123456') {
  + errorInfo.value = 'Password Mistake';
  } else {
  - this.errorInfo = '';
  + errorInfo.value = '';
  }
  - },
  + });
  +
  + return {
  + value,
  + errorInfo,
  + showKeyboard,
  + };
  },
  };
  ```
  