changelog for imshow changes

Author: nicolaskruchten

Diff for: CHANGELOG.md

@@ -4,6 +4,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [4.14.0] - UNRELEASED
 
+### Added
+
+- `px.imshow` now supports `facet_col` and `animation_frame` arguments for visualizing 3-d and 4-d images [2746](https://github.com/plotly/plotly.py/pull/2746)
+
 ### Updated
 
 - Updated Plotly.js to version 1.58.0. See the [plotly.js CHANGELOG](https://github.com/plotly/plotly.js/blob/v1.58.0/CHANGELOG.md) for more information. These changes are reflected in the auto-generated `plotly.graph_objects` module.