Armbian documentation hosted on Github pages

Pull request: auto rebuild and push to https://github.com/EvilOlaf/docupreview and publish at https://evilolaf.github.io/docupreview/ for reviewing.

PUSH: auto rebuild and push to https://github.com/EvilOlaf/docupreview and publish at https://github.com/EvilOlaf/docutest. This should be the official documentation then.

Web version is published here: https://evilolaf.github.io/docutest/
PDF version is published here: https://github.com/EvilOlaf/docutest/blob/master/pdf/document.pdf

Check runner files for details.