I see that asciidoctor.org itself has a navigation (top) bar. I'm guessing that the website was written using asciidoctor source files. Either way, how do I add a navigation bar using asciidoctor?
Update
This is possibly the wrong question to ask. Perhaps the right way to go is to use awestruct, Middleman, or Jekyll. Advice/suggestions are welcome.
Yes, the source is asciidoctor, but the site is using awestruct for the structure around the content. If you're looking at doing the same kind of thing, we recommend using some other site generation tool for the structure around the content.
Of course if you really want to do this in asciidoctor, you could. You'd need to create your own theme and craft the header that way, but it isn't really recommended because it ties your output to a medium.