changelog for hot reload alert fix

Author: alexcjohnson

CHANGELOG.md

@@ -2,6 +2,11 @@
 All notable changes to `dash` will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
+## [Unreleased]
+
+### Fixed
+- [#1953](https://github.com/plotly/dash/pull/1953) Fix bug [#1783](https://github.com/plotly/dash/issues/1783) in which a failed hot reloader blocks the UI with alerts.
+
 ## [2.2.0] - 2022-02-18
 
 ### Added