I see a lot of comments in this thread mentioning that it is only Ruby, but there is asciidoctor.js [1], a JS implementation. I'm using it at my company for the docs, together with Antora. It's the only docs system I have used extensively, but so far I didn't miss anything! We have quite a complex system with different components versioned independently, but it just works!
Edit in sublime Text, save, See the browser window on the other monitor (portrait orientation) update, tweak, repeat... That is my workflow for long and short Docs. AsciidoctorJs Chrome Extension is the glue.
[1] https://docs.asciidoctor.org/asciidoctor.js/latest/