## 添加图标

通过`icon`属性来给按钮添加图标

```json
{
    "body": [
        {
            "type": "button",
            "icon": "search",
            "shape": "circle"
        },
        {
            "type": "button",
            "icon": "search",
            "shape": "circle",
            "buttonType": "primary"
        }
    ]
}
```