update doc strings and add more dataclasses. Added screenshots of the GUI

overcooked_simulator/__init__.py

overcooked_simulator/counters.py

overcooked_simulator/gui_2d_vis/__init__.py

...ked_simulator/gui_2d_vis/images/overcooked-end-screen.png

...d_simulator/gui_2d_vis/images/overcooked-level-screen.png

...d_simulator/gui_2d_vis/images/overcooked-start-screen.png

overcooked_simulator/gui_2d_vis/overcooked_gui.py

overcooked_simulator/order.py

overcooked_simulator/overcooked_environment.py

overcooked_simulator/player.py

overcooked_simulator/utils.py

tests/test_start.py