This pull request introduces version 2.0.0 of the unicodeveloper/laravel-paystack package, featuring a major refactor of the SDK to improve maintainability, scalability, and developer experience.

Key updates include:

• Introduction of dedicated service classes for all Paystack API domains (Transaction, Customer, Subscription, Plan, Page, SubAccount, Bank).
• Implementation of a robust PaystackClient to handle HTTP requests with centralized error handling.
• Addition of TransRef utility class for unique transaction reference generation.
• Consistent and comprehensive PHPDoc annotations for all services and methods.
• Facade updates to expose new services seamlessly.
• Improved exception handling and code organization following SOLID principles.
• Updated documentation and usage examples.
• Configurable retry logic to PaystackClient via retry_attempts and retry_delay in config/paystack.php.
• Unit and Integration Test

This release lays a solid foundation for easier maintenance, adopting stricter typing, method signatures, and future feature additions.