Changelog entry

Author: RenaudLN

CHANGELOG.md

@@ -8,6 +8,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 - Fixed special cases with `px.sunburst` and `px.treemap` with `path` input ([#2524](https://github.com/plotly/plotly.py/pull/2524))
 
+### Added
+
+- New hexbin_mapbox trace in Plotly Express
+
 ## [4.8.1] - 2020-05-28
 
 ### Fixed