Clarifying how to deal with tempest-plugin during series

Previously the tempest plugins were driven by the legacy
`cycle-automatic` model. However this model have been abandoned.

The cycle-automatic release model is now better described by the
`cycle-with-intermediary` model combined with `stable-branch-type: none`

The `cycle-automatic` model was used by specific technical deliverables
that needed to be automatically released once at the end of a cycle.

the tempest-plugin are branchless and `cycle-with-intermediary`
however our process doesn't handle them at the end of the cycle
like did the `cycle-automatic`.

These changes clarifying that point.

Change-Id: I6b3619a44d0aea1fa4852e650cbafcb08c853353

doc/source/reference/deliverable_types.rst

@@ -67,6 +67,19 @@ or some other tool that builds on top of an existing release. The deadline
 for producing such a deliverable in a development cycle is the 'cycle-trailing
 Release Deadline', usually located 3 months after the coordinated release.
 
+.. _`type-tempest-plugin`:
+
+tempest-plugin
+==============
+
+This deliverable type indicates that a deliverable is a tempest plugin.
+those need to be automatically released once at the end of a cycle.
+Those may, optionally, also be released in the middle of the cycle.
+Those do not need a stable branch created. Those deliverables were previously
+managed by `the legacy cycle-automatic model`_.
+
+.. _`the legacy cycle-automatic model`: ./release_models.html#cycle-automatic
+
 .. _`type-other`:
 
 other

doc/source/reference/process.rst

@@ -1212,6 +1212,26 @@ R-2 week
 
 #. Process any standing RC1 deadline exceptions.
 
+#. Gracefully release tempest plugins with latest changes available. Tempest
+   plugins are branchless however they should be released on their ``HEAD`` at
+   the end of each cycle at least
+   (cf. `the legacy cycle automatic model <https://releases.openstack.org/reference/release_models.html#cycle-automatic>`_ and
+   `the tempest-plugin type <https://releases.openstack.org/reference/deliverable_types.html#tempest-plugin>`_).
+
+   - You can preview unreleased changes by using::
+
+      $ tox -e venv -- list-deliverables --type tempest-plugin
+      $ tools/list_unreleased_changes.sh wallaby <tempest-plugin-projects>
+
+   - Process auto release for those who need to be released::
+
+      $ tools/process_auto_releases.sh $series <tempest-plugin-projects-list>
+
+     .. warning::
+
+        Please use ``$series-tp-latest`` as gerrit topic.
+
+
 #. On the Monday, generate stable branches for all cycle deliverables that
    are still missing one.
 

doc/source/reference/release_models.rst

@@ -188,7 +188,7 @@ The "cycle-automatic" model is used by specific technical deliverables
 that need to be automatically released once at the end of a cycle.
 Those may, optionally, also be released in the middle of the cycle.
 Those do not need a stable branch created. This may be applied only
-to "tempest-plugin" or "other" deliverables.
+to ``tempest-plugin`` or ``other`` deliverables.
 
 * "cycle-automatic" deliverables will be automatically released by the
   release team once at the end of a cycle, using the current HEAD of the