Update CHANGELOG.md

Author: fverdugo

CHANGELOG.md

@@ -5,12 +5,17 @@ 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).
 
-## [0.5.0] - WIP
+## [0.5.0] - 2024-07-26
 
 ### Changed
 
 - `MPIArray` and `DebugArray` are now inmutable for performance reasons.
 
+### Fixed
+
+-  Many type instabilities.
+-  `mul!` (and also `consistent!`, `exchange!` ) allocation free for `MPIArray` (with `check-bounds=no`)
+
 ### Removed
 
 - `OldPSparseMatrix` and related functionality.