Convert published release notes to fragments

In order to generate a proper changelog as a part of releasing
process, we should maintain proper fragments instead of the
notes produced by `reno`.
This patch moves content to the expected place.

Change-Id: Icedb383b08a2e7ce60f5423912c09b2c499070ad
Signed-off-by: Dmitriy Rabotyagov <dmitriy.rabotyagov@cleura.com>

changelogs/fragments/volume_image_metadata_module.yaml

@@ -1,7 +1,6 @@
 ---
-features:
-  - |
-    Added a new ``openstack.cloud.volume_image_metadata`` module to manage
+minor_changes:
+  - Added a new ``openstack.cloud.volume_image_metadata`` module to manage
     Cinder volume image metadata via the ``os-set_image_metadata`` API.
     This enables correct preservation of image provenance and boot semantics
     for volumes, which cannot be achieved using regular volume metadata.

changelogs/fragments/volume_retype_module.yaml

@@ -0,0 +1,4 @@
+---
+minor_changes:
+  - Added a new ``openstack.cloud.volume_retype`` module to retype
+    Cinder volumes via the ``os-retype`` API.

releasenotes/notes/volume-retype-module-69df22ef9a10091d.yaml

@@ -1,5 +0,0 @@
----
-features:
-  - |
-    Added a new ``openstack.cloud.volume_retype`` module to retype
-    Cinder volumes via the ``os-retype`` API.