Add PendingReleaseNotes

This patch adds PendingReleaseNotes to track upcoming changes in
release notes.

Signed-off-by: Niraj Yadav <niryadav@redhat.com>

Author: black-dragon74

PendingReleaseNotes.md

@@ -0,0 +1,14 @@
+# v0.13.0 Pending Release Notes
+
+## Breaking changes
+
+## Features
+
+- allow override of precedence of key rotation and reclaim space related annotations
+using a ConfigMap key `schedule-precedence`.
+
+## NOTE
+
+- `schedule-precedence` defaults to `pvc` which reads the annotations in order of
+PVC > NS > SC. It can be set to `storageclass` to respect only the storageclass
+annotations.