Create Asciidoclet sample project

[msgilligan]

https://github.com/JGrenier/asciidoclet-sample is nice, but we should have a similar project under the asciidoctor organization that we can keep up to date and integrate with CI tools for testing and demonstration purposes.

[mojavelinux]

Perhaps we can follow the pattern used by the Maven and Gradle plugins? See https://github.com/asciidoctor/asciidoctor-maven-examples. If we only need a single example, we can drop the plural.

[msgilligan]

Maybe we could just start using Asciidoclet in all the existing examples.

I'd like to see a using-everything-asciidoctor project that kind-of mirrors the real-world usage I've been using on some of my projects (e.g. ConsensusJ) I also want an example that builds with Java 9/10 on Gitlab CI -- we can't do that for Asciidoclet itself, but we can do it for projects that use the latest Asciidoclet.

I'm also interested in learning how Groovy only publishes it's Asciidoctor site documentation which includes snippets from Unit tests -- only when those unit tests are actually passing.

[johncarl81]

We've tried to make the Asciidoclet project itself a self-example of using Asciidoclet... do you think a separate project would be able to highlight more or a different angle?

[msgilligan]

Yeah, the "dog food" approach is a good idea and we should definitely continue to do that.

I also want an example that builds with Java 9/10 on Gitlab CI -- we can't do that for Asciidoclet itself, but we can do it for projects that use the latest Asciidoclet.

I suppose it might be possible to use Java 9 in Java 8 mode to build it. I'm really interested in being able to produce the new HTML5 output. I'll look into that...