[skip ci] Update CHANGELOG.md

Author: mdbenito

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+- Improvements and fixes to notebooks
+  [PR #436](https://github.com/aai-institute/pyDVL/pull/436)
 - Fix initialization of `data_names` in `ValuationResult.zeros()`
   [PR #443](https://github.com/aai-institute/pyDVL/pull/443)
 - Using pytest-xdist for faster local tests