Asciidoctor is basically a Ruby gem (package), so if you want to try it out on Windows you simply install the Ruby language either via the Ruby Installer (https://rubyinstaller.org/) or use Scoop (https://scoop.sh/). Then you simply install the Asciidoctor gem with:
> gem install asciidoctor
Write an *.adoc plain text file using the Asciidoctor markup (https://asciidoctor.org/docs/asciidoc-syntax-quick-reference/) and compile to HTML (by default) using:
> asciidoctor Document_Name.adoc
which will give you Document_Name.html.
https://redhat-documentation.github.io/
There are instructions to convert from Word to Asciidoc: https://asciidoctor.org/docs/migrating-from-msword/