README.md

TopTip 顶部消息提示

```html
<h2 class="item-title">top-tip</h2>
  <div class="local-region">
    <top-tip v-model="show" entry-direction="down" content="顶部消息提示内容"/>
     参考文案
  </div>

<h-button class="button-class" type="rimless" shadow @click.native="showTopTip">TopTip</h-button>    
```