update changelog

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - [issue/267](https://github.com/podaac/l2ss-py/pull/261): Add xtrack and atrack dimension options for get_nd_indexers when bounding box subsetting is performed on SNDR.
 - Fix temporal subsetting ghrsst dataset by adding time delta to time variable.
 - Add a function to test ghrsst dataset ability to access variables when mask_and_scale is true. 
+- Update l2ss-py to allow the return of empty granules.
 ### Changed
 ### Deprecated 
 ### Removed