I'd describe Typst as somebody wanted a TeX reimplementation in Rust with better syntax and modern ideas, and made that their Masters projects.

It's markdown-like (but definitely not exactly CommonMark, don't expect that), with # acting as escape into the world of layout and programming. Templates are just functions that return a datatype called a content block, and so on.

https://typst.app/docs/tutorial/writing-in-typst/