Add docs publication trigger for all branches

[abelsromero]

What kind of change does this PR introduce? (check at least one)

• [ ] Bugfix
• [ ] Feature
• [x] Documentation
• [ ] Refactor
• [x] Build improvement
• [ ] Other (please describe)

What is the goal of this pull request?

Automatically publish docs on updates.

Are there any alternative ways to implement this?

Technically yes, but this is good and is already in use by asciidoctor-pdf.

Are there any implications of this pull request? Anything a user must know?

no

Is it related to an existing issue?

- [ ] Yes - [x] No *Finally, please add a corresponding entry to CHANGELOG.adoc*

[abelsromero]

Draft while waiting to get token configured.