Add release notes for 3.6.0 (#1406)

Signed-off-by: opensearch-ci <opensearch-infra@amazon.com>
(cherry picked from commit 0d76fe6)
Signed-off-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: github-actions[bot]

release-notes/opensearch-alerting-dashboards-plugin.release-notes-3.6.0.0.md

@@ -0,0 +1,24 @@
+## Version 3.6.0 Release Notes
+
+Compatible with OpenSearch and OpenSearch Dashboards version 3.6.0
+
+### Features
+
+* Add lookback window frontend support for PPL/SQL monitors ([#1379](https://github.com/opensearch-project/alerting-dashboards-plugin/pull/1379))
+
+### Bug Fixes
+
+* Fix acknowledge alerts modal to properly update table with acknowledged alerts instead of showing a stuck loading state ([#1363](https://github.com/opensearch-project/alerting-dashboards-plugin/pull/1363))
+* Fix broken anomaly detector monitor definition method in OpenSearch UI ([#1371](https://github.com/opensearch-project/alerting-dashboards-plugin/pull/1371))
+
+### Maintenance
+
+* Resolve CVE-2026-26996 and CVE-2026-2739 ([#1393](https://github.com/opensearch-project/alerting-dashboards-plugin/pull/1393))
+* Update lodash to 4.18.1 to address CVE-2026-4800 ([#1400](https://github.com/opensearch-project/alerting-dashboards-plugin/pull/1400))
+* Update lodash to 4.18.1 follow-up fix for CVE-2026-4800 ([#1404](https://github.com/opensearch-project/alerting-dashboards-plugin/pull/1404))
+* Upgrade to React 18 and fix unit tests to accommodate the upgrade ([#1369](https://github.com/opensearch-project/alerting-dashboards-plugin/pull/1369))
+
+### Refactoring
+
+* Refactor PPL alerting APIs to use v1 endpoints ([#1378](https://github.com/opensearch-project/alerting-dashboards-plugin/pull/1378))
+* Remove legacy and PPL alerting separation ([#1392](https://github.com/opensearch-project/alerting-dashboards-plugin/pull/1392))