Add some jobs for docs and releasenotes

* Use build-openstack-docs-pti job template for docs
* Use build-openstack-releasenotes job for release notes
  (We can't use the OpenStack releasenotes template as it includes
  publish jobs, stx needs its own)
* Add newnote tox environment as convenience for creating new release
  notes, re-using the releasenotes venv.
* Create a release summary note.

Change-Id: I5a610cfe271707fd704248ede0db75be6d031121
Signed-off-by: Dean Troyer <dtroyer@gmail.com>

.zuul.yaml

@@ -1,10 +1,14 @@
 ---
 - project:
+    templates:
+      - build-openstack-docs-pti
     check:
       jobs:
+        - build-openstack-releasenotes
         - openstack-tox-linters
         - openstack-tox-pep8
     gate:
       jobs:
+        - build-openstack-releasenotes
         - openstack-tox-linters
         - openstack-tox-pep8

releasenotes/notes/release-summary-c837becc3ca39fd4.yaml

@@ -0,0 +1,3 @@
+---
+prelude: >
+    These release notes cover the initial release of StarlingX.

tox.ini

@@ -63,6 +63,12 @@ commands =
     sphinx-build -a -E -W -d releasenotes/build/doctrees -b html releasenotes/source releasenotes/build/html
 whitelist_externals = rm
 
+[testenv:newnote]
+# Re-use the releasenotes venv
+envdir = {toxworkdir}/releasenotes
+deps = -r{toxinidir}/doc/requirements.txt
+commands = reno new {posargs}
+
 [testenv:api-ref]
 basepython = python3
 deps =