Update workflow and enhance README badges and info

Downgraded actions/checkout version in tests workflow from v6 to v4 for compatibility. Added Packagist badges, requirements, and credits sections to README for improved documentation and visibility.

Author: mischasigtermans

.github/workflows/tests.yml

@@ -34,7 +34,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@v4
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2

README.md

@@ -1,5 +1,8 @@
 # Laravel TOON
 
+[![Latest Version on Packagist](https://img.shields.io/packagist/v/mischasigtermans/laravel-toon.svg?style=flat-square)](https://packagist.org/packages/mischasigtermans/laravel-toon)
+[![Total Downloads](https://img.shields.io/packagist/dt/mischasigtermans/laravel-toon.svg?style=flat-square)](https://packagist.org/packages/mischasigtermans/laravel-toon)
+
 Token-Optimized Object Notation encoder/decoder for Laravel with intelligent nested object handling.
 
 TOON is a compact, YAML-like format designed to reduce token usage when sending data to LLMs. This package achieves **40-60% token reduction** compared to JSON while maintaining full round-trip fidelity.
@@ -283,6 +286,15 @@ public function index(Request $request)
 composer test
 ```
 
+## Requirements
+
+- PHP 8.2+
+- Laravel 10, 11, or 12
+
+## Credits
+
+- [Mischa Sigtermans](https://github.com/mischasigtermans)
+
 ## License
 
 MIT