Main menu, "jumpy" platforms, levels

Main menu:

• A simple main menu is added. The original one were animated for some technical reason I used the simple one now.

Levels:

• Two levels added and the platforms are mostly fixed so they can be played through.
• I couldn't find a "normal" solution for lifts and moving platforms in the 3D part of Godot but I could achieve this "jumpy" effect which I used as part of the level design.

Fight:

• You and the guardshards' attack range is lowered.
• The weapon laser effect should get stuck less often now.

Game over:

• If you fall off, then no problem, only your position get reset.
• If a guard shard decreases your hp below zero, the level reloads itself.