import zuul job settings from project-config

This is a mechanically generated patch to complete step 1 of moving
the zuul job settings out of project-config and into each project
repository.

Because there will be a separate patch on each branch, the branch
specifiers for branch-specific jobs have been removed.

Because this patch is generated by a script, there may be some
cosmetic changes to the layout of the YAML file(s) as the contents are
normalized.

See the python3-first goal document for details:
https://governance.openstack.org/tc/goals/stein/python3-first.html

Change-Id: I906e387d8f389b4c9718feac96cdede1ffb7487b
Story: #2002586
Task: #24302

.zuul.yaml

@@ -0,0 +1,14 @@
+- project:
+    templates:
+      - publish-openstack-sphinx-docs
+      - check-requirements
+      - release-notes-jobs
+    check:
+      jobs:
+        - openstack-tox-pep8
+    gate:
+      jobs:
+        - openstack-tox-pep8
+    post:
+      jobs:
+        - publish-openstack-python-branch-tarball