The footnote article you read is a proposal for specifications for the W3C. While we may include some things along those lines in paged.js later, the goal is to kickstart a conversation more than anything else today.
About a hugo theme for paged.js, you can add https://gitlab.pagedmedia.org/julientaq/pagedjs-hugo to any theme you’ll find around. You will need to change three lines in those themes, and you’ll be able to run Paged.js on any content you’d like.
I don’t think we’ll make a complete theme for making book with hugo soon, as it’s quite some work and we still have a lot to do on Paged.js, but we’ll hapily help anyone who would like to do so :).