Asciidoctor Highlight.js

We should take a look at @jirutka's Asciidoctor Highlight.js extension for it allows to use HLJS at convert time and free the final document from the need of loading HLJS package — thus making the docs truely portable to any HTML based format, including CHM, ePub, Mobi/Kindle, etc.

This project provides an Asciidoctor.js extension for highlighting source listing blocks using highlight.js right during document conversion (instead of in browser on client-side as the built-in highlight.js support).

It supports all Asciidoctor features such as callouts, passthroughs inside a code and all other substitutions, except highlighting of specified lines (attribute highlight).

This is an Asciidoctor.js extension, so it would require an alternative toolchain to the Ruby version, which might preclude using other Ruby-only extensions (not really sure of the implications). We might still rely on this for specific formats like CHM, etc.

Local tests and more digging are required, and this thread will be used to aggregate notes, links and discussions on evaluating the pros and cons of this alternative approach.