docs: update changelog

Author: Chemaclass

.github/CONTRIBUTING.md

@@ -102,12 +102,6 @@ If you are using NixOS, you can enter a shell with all the required tools using
 nix-shell --pure --run "./bashunit --simple"
 ```
 
-Alternatively, if you just need Bash for a one-time execution and don’t want to rely on the `shell.nix` file:
-
-```bash
-nix-shell -p bash --run "./bashunit --simple"
-```
-
 ## Coding Guidelines
 
 ### ShellCheck

CHANGELOG.md

@@ -2,7 +2,9 @@
 
 ## Unreleased
 
-- Fix parallel and `compgen` issue on NixOS
+- Fix NixOS support
+    - Fix parallel and `compgen`
+    - Use `command -v` instead of `which`
 
 ## [0.22.2](https://github.com/TypedDevs/bashunit/compare/0.22.1...0.22.2) - 2025-07-26