Sample: Basic Godot Game

While ModiBuff was tested with two basic prototypes, in Godot and Unity, it doesn't have a single good sample implementation to show basic usage.

This is where this issue comes in.

**The Game**

The game implementation is supposed to be **very** easy, as basic as a simplified Pokémon/turn-based JRPG, or some other basic real-time game. The only requirement is that ModiBuff.Core is used.

ModiBuff.Units can also be used, but it's not required. It's up to the developer if they want to implement their own Unit logic.
It's actually a bit preferred to not use ModiBuff.Units, since it comes with a huge implementation baggage, and it's easier to read and understand code, if we don't have to go through all the possible functionalities of the ModiBuff.Units `Unit`.

Note: for issues with UI connections with ModiBuff and other issues, please reach out. The library wasn't tested with all game scenarios.