amis能增加三级表头或者多级表头吗？

#### 是否关联于某个问题吗：
amis超级表头只支持两行表头

#### 预期的解决方案：
我想要三行或者更多行的表头

#### 其他可接受方案：
请简单描述其他你可以接受的效果...

#### 任何附加信息：
请添加任何可以补充说明上述问题的材料，例如图片或视频等...

Start by locating the amis table or super-header implementation and review how the current two-row header structure is represented. Confirm the expected configuration and rendering behavior for three or more header rows, then verify that the resulting table supports the multi-level example described in the issue.

Written by the indexing model from the issue text.