Adds pagerduty api update to changelog.

CHANGELOG.md

@@ -5,6 +5,7 @@
 * **Graph**: Thresholds for Right Y axis [#7107](https://github.com/grafana/grafana/issues/7107), thx [@ilgizar](https://github.com/ilgizar)
 * **Graph**: Support multiple series stacking in histogram mode [#8151](https://github.com/grafana/grafana/issues/8151), thx [@mtanda](https://github.com/mtanda)
 * **Alerting**: Pausing/un alerts now updates new_state_date [#10942](https://github.com/grafana/grafana/pull/10942)
+* **Alerting**: Support Pagerduty notification channel using Pagerduty V2 API [#10531](https://github.com/grafana/grafana/issues/10531)
 * **Templating**: Add comma templating format [#10632](https://github.com/grafana/grafana/issues/10632), thx [@mtanda](https://github.com/mtanda)
 * **Prometheus**: Support POST for query and query_range [#9859](https://github.com/grafana/grafana/pull/9859), thx [@mtanda](https://github.com/mtanda)