docs: standardize README.md structure

[usernane]

Documentation Location

README.md

Version

Current (main branch)

Issue Description

The README structure is inconsistent with the standard adopted across the WebFiori ecosystem (based on webfiori/http).

Current issues:

• Missing "License" section
• Missing "Support" section
• Missing "Changelog" section
• Missing "Contributing" section (has a note at end but not a formal section)

Suggested Improvement

Restructure the README to follow the ecosystem standard:

1. Title + one-line description
2. Centered badges (CI, Codecov, SonarCloud, Release, Downloads)
3. Table of Contents
4. Supported PHP Versions (build status table)
5. Key Features (bullet list)
6. Installation (composer require)
7. Quick Start / Basic Usage (working code examples)
8. [Library-specific sections]
9. Testing
10. Examples (link to examples directory)
11. Contributing
12. License
13. Support (issues link)
14. Changelog