Level system, code improvements and more

Hello, I have been working on my game since the last post.

A few things have changed. The main change is that most of the code has been rewritten. I did this because the old code did not suit the game. The things that have been changed are the player can only have 1 weapon, improvement to the player input and improvements to the AI.

I have also added a level up system. When the player kills an enemy. The player will get XP. Each character will have their own XP and level. When a character level up their stats will improve.

My next goal is to start on the item inventory and the game first boss fight.