Add diagram support via kroki.io

[wfouche]

Asciidoctor.js supports diagram via kroki.io.

What is required to get diagram (kroki.io) support in asciidocLIVE? Hopefully just an upgrade to a new version of Asciidoctor.js.

See https://github.com/Mogztter/asciidoctor-kroki for details.

The Chrome Asciidoc Preview plugin also support kroki diagrams.

https://chrome.google.com/webstore/detail/asciidoctorjs-live-previe/iaalpfgpbocpdfblpnhhgllgbdbchmia?hl=en

[wfouche]

Dropped.