How to create new syntax highlighting?

[nottsknight]

How are new sets of syntax highlighting added? Is it possible for a user to add them in a project, or do they have to be 'baked in' to the plugin? I'm writing a guide on ANTLR for my students and it'd be really helpful to have syntax highlighting in the examples.

[burrbull]

syntax highlighting is not part of codly.
You can add new highlighting by changing theme path for raw:
https://typst.app/docs/reference/text/raw/#parameters-theme

For example https://github.com/filmgirl/TextMate-Themes/