DEV: Update changelog

Author: LucasVGon

CHANGELOG.md

@@ -31,7 +31,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 Attention: The newest changes should be on top -->
 
 ### Added
-
+- EHN: Addition of ensemble variable to ECMWF dictionaries [#842] (https://github.com/RocketPy-Team/RocketPy/pull/842) 
 - ENH: Discretized and No-Pickle Encoding Options [#827] (https://github.com/RocketPy-Team/RocketPy/pull/827)
 - ENH: Add the Coriolis Force to the Flight class [#799](https://github.com/RocketPy-Team/RocketPy/pull/799)