update changelog

Author: emilykl

CHANGELOG.md

@@ -11,6 +11,7 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Updated plotly.py to use base64 encoding of arrays in plotly JSON to improve performance.
 - Add `subtitle` attribute to all Plotly Express traces
 - Make plotly-express dataframe agnostic via Narwhals [#4790](https://github.com/plotly/plotly.py/pull/4790)
+- Add `plotly[express]` extra for easily installing Plotly Express dependencies [#4644](https://github.com/plotly/plotly.py/pull/4644)
 
 ## [5.24.1] - 2024-09-12