If you are interested in creating custom syntaxes highlighting definitions for Drafts, this forum category has been created as a place to get help and ask questions.
The syntaxes article in the User Guide is the best starting point to understand what syntax definitions are, what they are for, and how to go about creating them:
Once you get through that, export several of the built-in syntaxes as files, and open them in a JSON-friendly editor. We have also created samples for some specific techniques, and popular requested syntaxes, like AsciiDoc and Fountain. These can be found in the syntaxes are of the Directory.