Draft documentation component set up and production promotion guidelines

[graphitefriction]

Once the production CI for docs.asciidoctor.org is set up and the site publishing, other Asciidoctor projects can add their documentation to it. We can make this process easier by providing some quick guidelines that provide an overview of the playbook and UI repositories, publishing process (CI jobs, hooks/actions, etc.), and docs component architect. This document should point to as much existing documentation as possible (Antora docs, structure of Core and Asciidoctor.js components as examples, etc.).

Additionally, are there any specific steps or criteria before before a docs component is promoted to production the first time?

[mojavelinux]

It seems to me that if we just document the workflow, then we catch like 80% of this.

There's also the policy for how to manage versions and branches, which we just laid out in #15 (comment).

I have to think about what would be required for a new entry. Although, the Gradle plugin is asking that very question. (See asciidoctor/asciidoctor-gradle-plugin#102 (comment)).

[mojavelinux]

Here's some raw material for this issue. https://gitlab.com/antora/docs.antora.org