Add change log for 0.5.1 release

CHANGELOG-0.5.md

@@ -1,3 +1,34 @@
+# Release notes for v0.5.1
+
+[Documentation](https://docs.k8s.io/docs/home)
+# Changelog since v0.5.0
+
+## Changes by Kind
+
+### Feature
+
+- Add `process_start_time_seconds` metric. ([#106](https://github.com/kubernetes-csi/external-resizer/pull/106), [@Jiawei0227](https://github.com/Jiawei0227))
+- Adding configurable QPS and Burst to k8s client and use a separate client for leader election. ([#91](https://github.com/kubernetes-csi/external-resizer/pull/91), [@RaunakShah](https://github.com/RaunakShah))
+- Pods watch is an expensive operation. Hence make the feature of handling volume in use errors optional, by registering pod informer based on a feature gate ([#89](https://github.com/kubernetes-csi/external-resizer/pull/89), [@saikat-royc](https://github.com/saikat-royc))
+
+### Uncategorized
+
+- Build with Go 1.15 ([#98](https://github.com/kubernetes-csi/external-resizer/pull/98), [@pohly](https://github.com/pohly))
+- Publishing of images on k8s.gcr.io ([#84](https://github.com/kubernetes-csi/external-resizer/pull/84), [@pohly](https://github.com/pohly))
+
+## Dependencies
+
+### Added
+_Nothing has changed._
+
+### Changed
+- github.com/kubernetes-csi/csi-lib-utils: [v0.7.0 → v0.7.1](https://github.com/kubernetes-csi/csi-lib-utils/compare/v0.7.0...v0.7.1)
+
+### Removed
+_Nothing has changed._
+
+# Release notes for v0.5.0
+
 # Changelog since v0.4.0
 
 ## New Features