Cleanup release notes for 3.9.0 release

Change-Id: I6786fe67928d4f3d72cb4751fb70b67dccaa11e2

releasenotes/notes/bug-1499657-eeb260849febacf3.yaml

@@ -1,6 +1,5 @@
 ---
 fixes:
   - |
-    Options ``--parents`` and ``--children`` don't work in ``project show``
-    command, fix the issue.
+    Fix ``--parents`` and ``--children`` options in ``project show`` command.
     [Bug `1499657 <https://bugs.launchpad.net/python-openstackclient/+bug/1499657>`_]

releasenotes/notes/bug-1666780-c10010e9061689d3.yaml

@@ -1,11 +1,12 @@
 ---
 features:
   - |
-    Support list commands by group name keyword. Add ``--group`` option to
-    filter the commands by group name keyword, like: --group volume, list all
-    openstack.volume.v2 (cinder) commands.
-    That support the scenario that users need to know the current support
-    commands of some OpenStack services(nova, neutron, cinder and so on) in
-    OSC, and make it easier for users to find out the related commands that
-    they care about.
+    Add ``--group`` option to the ``command list`` command to filter the
+    commands by group name: ``openstack command list --group volume`` will
+    list all Volume commands for the selected API version.  Use
+    ``--os-XXXX-api-version`` to select a specific API version for the desired APIs.
+
+    This provides an alternative to searching help output to list the comamnds
+    available for specific APIs.  Note that the ``--group`` argument is used as
+    a simple substring search in the Command Group column.
     [Bug `1666780 <https://bugs.launchpad.net/python-openstackclient/+bug/1666780>`_]

releasenotes/notes/bug-1667699-6dad786b128ca8b5.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fix the ``Ethertype`` column output of ``security group rule list`` command.
+    [Bug `1667699 <https://bugs.launchpad.net/python-openstackclient/+bug/1667699>`_]