Setup repo for usual Sphinx location:
* content lives in doc/source
* Add tox.ini for building with linter and docs job
* Add doc/source/conf.py for Sphinx
* Add index file to build a manual
* Add jobs for Zuul; note that tox-linters is non-voting for now, fixing
issues can be done as followup.
The docs job has Sphinx warnings disabled, this will be a followup as
well.
* Add .gitignore for usual build artefacts
Change-Id: Ie7af4b6bd661e61180528cc1ecf3076e3e95590b
Andreas Jaeger