Add a job to promote docs.airshipit.org content
Add a job to promote docs.airshipit.org content

A new documentation site is being added for the Airship project, so
provide a job to perform publication in the promote pipeline after
successful gating of changes.

Change-Id: I1fb3bab8902ec8266696a82d77246c346fe642d5

openstack-infra/project-config,openstack-infra/project-config