Add 2.18.0 release notes (#928)

Signed-off-by: Daniel Widdis <[email protected]>

release-notes/opensearch-flow-framework.release-notes-2.18.0.0.md

@@ -0,0 +1,19 @@
+## Version 2.18.0.0
+
+Compatible with OpenSearch 2.18.0
+
+### Features
+- Add ApiSpecFetcher for Fetching and Comparing API Specifications ([#651](https://github.com/opensearch-project/flow-framework/issues/651))
+- Add optional config field to tool step ([#899](https://github.com/opensearch-project/flow-framework/pull/899))
+
+### Enhancements
+- Incrementally remove resources from workflow state during deprovisioning ([#898](https://github.com/opensearch-project/flow-framework/pull/898))
+
+### Bug Fixes
+- Fixed Template Update Location and Improved Logger Statements in ReprovisionWorkflowTransportAction ([#918](https://github.com/opensearch-project/flow-framework/pull/918))
+
+### Documentation
+- Add query assist data summary agent into sample templates ([#875](https://github.com/opensearch-project/flow-framework/pull/875))
+
+### Refactoring
+- Update workflow state without using painless script ([#894](https://github.com/opensearch-project/flow-framework/pull/894))