update changelog

Author: jonhealy1

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 - Added `datetime_frequency_interval` parameter for `datetime_frequency` aggregation. [#294](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/294)
 - Added rate limiting functionality with configurable limits using environment variable `STAC_FASTAPI_RATE_LIMIT`, example: `500/minute`. [#303](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/303)
+- Added publish.yml to automatically publish new releases to PyPI [#305](https://github.com/stac-utils/stac-fastapi-elasticsearch-opensearch/pull/305)
 
 ### Changed