> 
> Also, I’ve bumped into the Info page about using Tree Sitter for multi language modes.  Is there an example of a mode that uses multiple languages that I can look at for ideas?

I’ve written a tiny html mode to make sure the multi language APIs make sense. Hopefully I’ll find time to expand it a bit and add a tree-sitter HTML mode. (If you are interested in doing it, please go ahead.)

Yuan