add key path change to changelog

CHANGELOG.md

@@ -8,6 +8,23 @@ Remember to align the itemized text with the first line of an item within a list
 
 ## jax 0.4.6
 
+* Changes
+  * `jax.tree_utils` now contain a set of APIs that allow user to define keys for their
+    custom pytree node. This includes:
+    * `tree_flatten_with_path` that flattens a tree and return not only each leaf but 
+      also their key paths.
+    * `tree_map_with_paths` that can map a function that takes the key path as argument.
+    * `register_pytree_with_keys`` to register how the key path and leaves should looks 
+      like in a custom pytree node.
+    * `keystr` that pretty-prints a key path.
+
+* Deprecations
+  * The old key-path APIs in `jax.tree_util` are deprecated and will be removed 3 months
+    from Mar 10 2023:
+    * `register_keypaths`: use {func}`jax.lax.register_pytree_with_keys` instead.
+    * `AttributeKeyPathEntry` : use `GetAttrKey` instead.
+    * `GetitemKeyPathEntry` : use `SequenceKey` or `DictKey` instead.
+
 ## jaxlib 0.4.6
 
 ## jax 0.4.5 (Mar 2, 2023)