message: [Doc] NoticeBar: update demo
diff: @@ -13,36 +13,48 @@ Vue.use(NoticeBar);
  ```html
  <van-notice-bar
  - text="Only those who have the patience to do simple things perfectly ever acquire the skill to do difficult things easily."
  + text="Notice Content"
  left-icon="volume-o"
  />
  ```
  -#### Mode
  +#### Disable scroll
  ```html
  -<van-notice-bar mode="closeable">
  - Only those who have the patience to do simple things perfectly ever acquire the skill to do difficult things easily.
  +<van-notice-bar :scrollable="false">
  + Notice Content
  </van-notice-bar>
  +```
  -<van-notice-bar mode="link">
  - Only those who have the patience to do simple things perfectly ever acquire the skill to do difficult things easily.
  +#### Wrapable
  +
  +```html
  +<van-notice-bar wrapable :scrollable="false">
  + Notice Content
  </van-notice-bar>
  ```
  -#### Disable scroll
  +#### Mode
  ```html
  -<van-notice-bar :scrollable="false">
  - Only those who have the patience to do simple things perfectly ever acquire the skill to do difficult things easily.
  +<van-notice-bar mode="closeable">
  + Notice Content
  +</van-notice-bar>
  +
  +<van-notice-bar mode="link">
  + Notice Content
  </van-notice-bar>
  ```
  -#### Wrapable
  +### Custom Style
  ```html
  -<van-notice-bar wrapable :scrollable="false">
  - Only those who have the patience to do simple things perfectly ever acquire the skill to do difficult things easily.
  +<van-notice-bar
  + color="#1989fa"
  + background="#ecf9ff"
  + left-icon="info-o"
  +>
  + Notice Content
  </van-notice-bar>
  ```
  