Reset changelog after 2.18.0 release (#950)

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

CHANGELOG.md

@@ -9,32 +9,16 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.1.0/)
 ### Bug Fixes
 ### Infrastructure
 - Set Java target compatibility to JDK 21 ([#730](https://github.com/opensearch-project/flow-framework/pull/730))
-- Add knowledge base alert agent into sample templates ([#874](https://github.com/opensearch-project/flow-framework/pull/874))
 
 ### Documentation
-- Add alert summary agent template ([#873](https://github.com/opensearch-project/flow-framework/pull/873))
-- Add alert summary with log pattern agent template ([#945](https://github.com/opensearch-project/flow-framework/pull/945))
-
 ### Maintenance
 ### Refactoring
 
-## [Unreleased 2.x](https://github.com/opensearch-project/flow-framework/compare/2.17...2.x)
+## [Unreleased 2.x](https://github.com/opensearch-project/flow-framework/compare/2.18...2.x)
 ### 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))
-- Add API Consistency Tests with ML-Common and Set Up Daily GitHub Action Trigger([#908](https://github.com/opensearch-project/flow-framework/issues/908))
-
 ### 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))
-
 ### Infrastructure
 ### Documentation
-- Add query assist data summary agent into sample templates ([#875](https://github.com/opensearch-project/flow-framework/pull/875))
-- Add suggest anomaly detector agent into sample templates ([#944](https://github.com/opensearch-project/flow-framework/pull/944))
-
 ### Maintenance
 ### Refactoring
-- Update workflow state without using painless script ([#894](https://github.com/opensearch-project/flow-framework/pull/894))