Tidy up release notes for Stein release

releasenotes/notes/add-ceilometer-ipmi-b646f886666889a1.yaml

...es/notes/add-cinder-quobyte-support-0de697a0800fb962.yaml

releasenotes/notes/add-cyborg-c7ee957a2cbe8e99.yaml

...notes/notes/add-migration-interface-b53da3ff04c2a7fe.yaml

releasenotes/notes/add-monasca-grafana-c31d4407c33939e4.yaml

...notes/notes/add-monasca-log-metrics-370846df015ff96a.yaml

...senotes/notes/add-monasca-persister-c8fdd3d127b2438e.yaml

releasenotes/notes/add-monasca-thresh-f7a860ce996684f9.yaml

.../notes/add-neutron-metering-support-4266364hudc5l80c.yaml

...tes/notes/add-octavia-custom-policy-6a55d8cd951ce639.yaml

...notes/add-octavia-network-interface-4e54077c1ca2a2f4.yaml

...nfigure-nova-serial-console-timeout-7cfc764a0c19eb01.yaml

...dd-prometheus-as-vitrage-datasource-3439b3f9925b8e8e.yaml

...d-prometheus-elasticsearch-exporter-4d9b75b5cb8801d1.yaml

...s/add-prometheus-openstack-exporter-8fd7b0e6c8e71649.yaml

releasenotes/notes/add_monasca_agent-2b3b2f484a9e7168.yaml

releasenotes/notes/add_qume_options-8e9f040d0bc36fe6.yaml

releasenotes/notes/add_ulimit_support-35e8799f29a44d12.yaml

...es/notes/allow-disabling-keepalived-310321889a848edf.yaml

releasenotes/notes/config-nova-release-97e6fc526a94740e.yaml