Added 3 new classes (Area/Player/Car).

Area.java :
===========
- description of an area (array[][]).
- declarations of sizeMax, size.
- 2 empty constructors (default or custom size) -> TO COMPLETE NEXT TIME
- getSize() to get a size of an area.

Car.java :
==========
- empty class now -> TO COMPLETE NEXT TIME

Player.java :
=============
- empty class now -> TO COMPLETE NEXT TIME