Remove DS_Store

Add state design pattern example

Add flyweight design pattern example

Change visitor design pattern example

Update visitor design pattern example

Add visitor design pattern example

Add playground with Memento design pattern example

Add playground with Mediator design pattern example

Add playground with Command design pattern example

Add playground with Iterator, Composite and Chain of Responsibility design patterns examples

Add proxy design pattern example

Add template method design pattern example

Add prototype design pattern example

Add playgrounds with Adaptor and Facade design patterns

Add playground with Decorator design pattern example