- Optimize imports
- Remove unused fields
- Remove system outs in the server classes

- Updated necessary methods
- Update readme
- Rename pool to clientPool (in addition to gamesPool)

Fixing getAndSetNextPlayer() Test.

- Added more validations to getPort() in InputHandler.java

- Fixed a rare error in the placeFirstCard() method in DiscardPile.java, where the first card was invalid, and the second card was a colored number card.
- Implemented the rule that if you draw a card and this card is a valid card to play, you can play it immediately in the same turn.
- Implemented exception prevention for the broadcast() method in Server.java.

- Move isValidCard() from Game to Card class

Adding Test classes GameTest, PlayerTest, CardTest.