[Bug] getCellRange api error

[fangsmile]

Version

develop

Link to Minimal Reproduction

1

Steps to Reproduce

1

Current Behavior

https://visactor.io/vtable/demo/custom-render/custom-merge-layout

getCellRange(0,7) 获取的合并范围有误

Expected Behavior

1

Environment

- OS:
- Browser:
- Framework:

Any additional comments?

No response

[fangsmile]

getCellRange 获取合并范围接口需要补充到网站接口中