Improve README.md

[google-labs-jules]

This commit completely revamps the README.md file to provide a comprehensive guide for users of the Laravel Auth Pro package. The new README includes:

• A clear overview of the package's features.
• Detailed installation and configuration instructions, including how to publish assets and run migrations.
• Comprehensive usage examples for all supported authentication methods: Email/Password, One-Time Password (OTP), and OAuth.
• An API reference section that documents the main AuthPro facade, the AuthServiceInterface, and the various credential classes.
• Links to contribution guidelines and the license.
• Standard badges for build status, downloads, version, and license.