Add Type Annotations throughout the Codebase #91

Not all variable declarations have a type annotation, which makes the code less documented and readable. I want to add type annotations to as many declarations as possible. Most of these should be straightforward, but I'll need to look through the documentation to find return types for methods such as config.save_file().

Notes:

• Percentages are typically noted as floats. This is because neededPercentageToPass in DieManager.gd was already noted as a float and that they can easily become a float by doing something like a 1/3 chance for something to occur.
• Certain directories weren't touched like Experiments, because I don't have the context needed to understand and touch them. Also they seem more like personal modifications and I don't want to mess with the vision

Commits:

1. Godot Game Code -> CharacterMenu, DiceRoller and Import Character