docs: move changelog update to unreleased

Author: Yuri Zmytrakov

CHANGELOG.md

@@ -8,6 +8,10 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+### Added
+
+- Added `USE_DATETIME` environment variable behavior to set datetime filtering logic. [#443](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/443)
+
 ### Changed
 
 - updated `numReturned` & `numMatched` fields in itemCollection return to `numberReturned` & `numberMatched`. [#446](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/446)
@@ -16,7 +20,6 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ### Added
 
-- Added `USE_DATETIME` environment variable behavior to set datetime filtering logic. [#443](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/443)
 - `STAC_INDEX_ASSETS` environment variable to allow asset serialization to be configurable. [#433](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/433)
 - Added the `ENV_MAX_LIMIT` environment variable to SFEOS, allowing overriding of the `MAX_LIMIT`, which controls the `?limit` parameter for returned items and STAC collections. [#434](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/434)
 - Sort, Query, and Filter extension and functionality to the item collection route. [#437](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/437)