WIP Couch Multiplayer and WIP Attacks

(In the previous update) Added a multiplayer mode, still unfinished. At the moment there can be two players (screenshot 1) with separate scores. You can select the second player's keybindings after clicking "multiplayer" in the main menu (I haven't chosen the default ones yet). There is still a single crafting menu in the multiplayer mode that, in the future, will be divided into two or more.

There is also a new kind of move, the hold attack (you can hold down the button to keep the attack going), which come in two new moves: The Charged hit (2) for the sword. Hold to aim, and then, release the power. You can launch yourself if you charge it enough; The spear's Glide (3). Hold to attack upward and get a small jump boost.

Added a new WIP mechanic too: if you run past a ledge (4) and move backwards right after falling, you will be snapped under that ledge (5), so you can avoid the attack and run away or counter.