[Behavioral 8] State design pattern example with TypeScript

The State Design Pattern is a behavioral design pattern that allows an object to alter its behavior when its internal state changes. It encapsulates state-specific logic into separate classes, promoting cleaner and more maintainable code.

In TypeScript, the pattern can be implemented effectively using interfaces, classes, and polymorphism.

Advantages:
1. Encapsulation of State-Specific Logic: Each state has its own class, making code easier to manage.
2. Open/Closed Principle: Adding new states is straightforward without modifying existing ones.
3. Single Responsibility Principle: The context class focuses on delegating behavior, while states handle specific actions.