DOC: Update CHANGELOG after merging #263 [skip ci]

doc/CHANGELOG.md

@@ -4,6 +4,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+### Fixed
+- Vendor code from evfuncs and birdsong-recognition-dataset packages,
+  to reduce the number of dependencies and make sure the code is maintained
+  [#263](https://github.com/NickleDave/crowsetta/pull/263).
+  Fixes [#262](https://github.com/NickleDave/crowsetta/issues/262).
+
 ## 5.0.1 -- 2023-05-27
 ### Fixed
 - Fix bug in "generic-seq" format; use validated dataframe