Move players and camera out of grid node

Remove some useless dependencies.

Game.gd

@@ -1,13 +1,13 @@
 extends Node2D
 
-onready var cam = $Grid/Camera1
+onready var cam = $MainCamera
 var players = []
 var dist_max = 900
 var zoom_rate = 0.001
 
 func _ready():
-	players.append($Grid/Player1)
+	players.append($Player1)
-	players.append($Grid/Player2)
+	players.append($Player2)
 
 func _process(d):
 	center_camera()