Hmm yeah I guess what I really want is a maekdown style mini-language that compiles to tab format.
"VexTab is a language that allows you to easily create, edit, and share standard notation and guitar tablature. Unlike ASCII tab, which is designed for readability, VexTab is designed for writeability."
https://vexflow.com/vextab/tutorial.html
There's no such thing as "Tab format". Tabs are just ascii text.
Isn't that what LilyPond does, more or less?
"VexTab is a language that allows you to easily create, edit, and share standard notation and guitar tablature. Unlike ASCII tab, which is designed for readability, VexTab is designed for writeability."
https://vexflow.com/vextab/tutorial.html