Since upstream Panko project has retired, we deprecating role for it.
Since we might want to get some patches in for stable branches, we're
deprecating role instead of retiring it.
Depends-On: https://review.opendev.org/c/openstack/project-config/+/799802
Change-Id: I35e008bcc9b35373dc6db2672ee1cabb328e7f9b
The content in master came from the stable/pike branch, so we change
all the branch references to work with master instead.
We also add various scaffolding and update various files so that
it matches the right content for master and will be able to build
docs/releasenotes when imported into openstack-infra.
Dmitriy Rabotyagov