Publish Zun-tempest-plugin's documentation
Publish Zun-tempest-plugin's documentation

* Add template to publish documentation.
* Add check-requirements as well

Change-Id: Ibddeacd8d04a063db8046c36226d96fed8273e4b
Closes-Bug: #1738111

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