Update 4.7.0 release notes

Author: Jonathan S. Katz

docs/content/releases/4.7.0.md

@@ -19,6 +19,7 @@ PGO 4.7.0 release includes the following software versions upgrades:
 
 - [PostGIS](https://postgis.net/) 3.1 is now available.
 - [pgBackRest](https://pgbackrest.org/) is now at version 2.33.
+- [pgMonitor](https://github.com/CrunchyData/pgmonitor) is now at 4.5.0. Grafana 7.4 is now required for visualizing the exported metrics.
 - [Patroni](https://patroni.readthedocs.io/) is now at version 2.0.2.
 - [pgBouncer](https://www.pgbouncer.org/) for CentOS 8 / UBI 8 is rebuilt to use the evdns for its async DNS backend.
 
@@ -89,6 +90,16 @@ and the Postgres Operator will create `hippo` from `elephant`. This also works b
 
 Note that the Postgres Operator needs to have [sufficient privileges in both namespaces](https://access.crunchydata.com/documentation/postgres-operator/latest/architecture/namespace/) to use this feature. For more information, please read about [Namespace Management](https://access.crunchydata.com/documentation/postgres-operator/latest/architecture/namespace/) in the documentation.
 
+## Monitoring Improvements
+
+This release brings several enhancements to monitoring Postgres clusters managed by PGO, including support for Grafana 7.4. These include:
+
+- New query performance insights, including the standard "top N" views (longest running queries, average runtime, total queries run) to help with performance troubleshooting.
+- Enhancements to information available about the state of backups, including the backup recovery window, the total number of missing WAL archives, the total size of backups, and more.
+- A new "alerting dashboard" that provides summary information about system health and alert history.
+
+There are also general improvements to the overall user experience of the monitoring visualizations.
+
 ## Enable / Disable TLS in Active PostgreSQL Clusters
 
 It's common to begin designing a Postgres cluster in development and then, upon bringing it to production, add TLS support to it.