V0.23 More Items!

Part of this version was to redesign some part of the code and fixing bugs. Also took the time to add a good amount of new items.

• Fix some bugs
• Refactoring part of the code
• Reduce the amount of time the cell shooter appear
• Added new items (now at 78!)
• Support more than 4 visible drones
• Continue the work on the second zone
• Removed the second zone for the demo