One use I'd have for this is company wikis that you want to give folks easy offline access to (maybe the wiki has documentation that's useful at sites that don't have cellular coverage). Cool! It would be especially cool to have a version that didn't require the separate serving process - even though it's nifty you can package up a whole site as a single binary. Maybe a single HTML entrypoint shim with a bit of javas…
Submitting this to Hacker News is the right place! Thanks for your idea. I will consider implementing that :) Also, in my mind, I already have a script/program to convert HTML to Markdown, so it could actually store everything on disk as a folder of Markdown files, and then commit them to a Git repo.
Epub would also be a great target.