Prepare changelog for 0.29.0 release

Signed-off-by: Paul-Elliot <[email protected]>

Author: panglesd

Diff for: CHANGES.md

@@ -1,13 +1,13 @@
-unreleased
+0.29.0 (06/02/2023)
 ------------------
 
 - Remove `File_path` exports. (#381, @ceastlund)
 
+- Add `Ppxlib.Expansion_helpers` with name mangling utilities from ppx_deriving (#370, @sim642)
+
 0.28.0 (05/10/2022)
 -------------------
 
-- Add `Ppxlib.Expansion_helpers` with name mangling utilities from ppx_deriving (#370, @sim642)
-
 - Make `esequence` right-associative. (#366, @ceastlund)
 
 - Deprecate unused attributes in `Deriving.Generator` (#368, @sim642)