### 基本用法

``` html
<u-card title="卡片">
    <u-skeleton></u-skeleton>
</u-card>
```

### 卡片分组

``` html
<u-card title="卡片">
    <u-card-group title="卡片分组">
        <u-skeleton></u-skeleton>
    </u-card-group>
    <u-card-group title="卡片分组">
        <u-skeleton></u-skeleton>
    </u-card-group>
</u-card>
```
