Add another changelog entry

Author: Greenscreen23

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project does **not** adhere to [Semantic Versioning](https://semver.org
 
 -   Add behaviors button now opens towards the top.
 -   Simulated regions can now send patients to any hospital. The hospitals tab was removed.
+-   In the frontend for the assign leader behavior, the vehicle of the currently leading personnel is displayed
 
 ### Fixed