thanx for mentioning docToolchain here!
yes, docToolchain builds on top of asciidoctorj and the gradle asciidoctor plugin.
It tries to make the use of asciidoctor even easier, by providing the full toolset provided by the asciidoctor community in one build, mainly asciidoctor, asciidoctor-diagram and asciidoctor-pdf. (this isn't as easy at it seems :-)
In addition, it show how to create further output formats like MS Word and it can export the docs to confluence.
Furthermore it show how to use scripting to include the export of diagrams from other tools (sparx, visio) in your automatic build and also how to include other sources like excel and powerpoint.
Here is an architectural overview: