Add v4.5.0 release notes

Author: Jonathan S. Katz

docs/content/releases/4.5.0.md

@@ -1,4 +1,11 @@
-Crunchy Data announces the release of the PostgreSQL Operator 4.5.0 on September XX, 2020.
+---
+title: "4.5.0"
+date:
+draft: false
+weight: 70
+---
+
+Crunchy Data announces the release of the PostgreSQL Operator 4.5.0 on October 2, 2020.
 
 The PostgreSQL Operator is released in conjunction with the [Crunchy Container Suite](https://github.com/CrunchyData/crunchy-containers/).
 
@@ -143,6 +150,7 @@ To remove an annotation, one follows the format:
 - Ensure pgBackRest S3 Secrets can be upgraded from PostgreSQL Operator 4.3.
 - Ensure pgBouncer Port is derived from the cluster's port, not the Operator configuration defaults.
 - External WAL PVCs are only removed for the replica they are targeted for on a scaledown. Reported by (@dakine1111).
+- When deleting a cluster with the `--keep-backups` flag, ensure that backups that were created via `--backup-type=pgdump` are retained.
 - Return an error if a cluster is not found when using `pgo df` instead of timing out.
 - pgBadger now has a default memory limit of 64Mi, which should help avoid a visit from the OOM killer.
 - The Postgres Exporter now works if it is deployed in a TLS-only environment, i.e. the `--tls-only` flag is set. Reported by (@shuhanfan).