Alternative checkboxes support

Hi, and thanks for supporting this great theme in Obsidian!

Are there any plans to implement alternative checkboxes (like the [ITS Theme](https://github.com/SlRvb/Obsidian--ITS-Theme/blob/main/Guide/Alternate-Checkboxes.md), among several others, does)?

I personally don't use all of these, but for my task management workflow supporting at least "cancelled" and "in progress" tasks would be a big help.

Thanks again!