refactor: optimize code based on review feedback [200~- Extract skip_empty_lines function to remove duplication - Add parse_ingredient_line function with explicit validation - Use enumerate for cleaner file merging logic - Replace os.path with modern pathlib.Path - Add error protection for ingredient count parsing - Improve code structure and documentation~

feat: add main program and documentation

feat: implement file merging (Task 3)

feat: add shopping list functionality (Task 2)

feat: implement cook book reader (Task 1)

build: initialize project with basic structure