Added docstrings to constructors of several classes in various modules to improve code readability and maintainability. Also, explicit type hints were provided for the fields in these classes aiding in better understanding of the data types used across the codebase.

Implemented multiple code adjustments across various Python modules, including renaming variables for clarity and improving data type definition. Added comprehensive docstrings to all functions and classes to enhance code readability and maintainability. Corrected a bug in debug parameter where it incorrectly employed args.debug, replacing it with args.do_study for correct implementation.

The updates address issues with empty meal lists during order creation. When no meals are available, no orders will be created, returning empty lists instead. Furthermore, the mandatory meal assertion in the environment's validate_environment method has been commented out. The meal list in the level1 config has been updated to only include 'Burger'.

The 'recipes.py' module is renamed to 'validation.py' and the 'RecipeValidation' class is renamed to 'Validation'. The code is refactored to use f-strings for better readability. Graph generation has also been improved by simplifying the way edges are added and returning information as a dictionary. An unnecessary png file generation has been removed. Changes have been made where these classes are imported and used.

The module 'game_items' was renamed to 'items'. Every reference to this module across different source code files was consequently updated to reflect this change.

The configurations for study level and game layout have been updated to accommodate new requirements. Additionally, a RecipeValidation class has been created to handle recipe graphs, which is now being utilized in both the drawing and game_server files. This is instead of the previous more scattered approach of handling such graphs within other classes or standalone functions. These changes make the code more organized and efficient.