Ender 5 dual Z axis

Dual Z axis support for the Ender 5.
It keeps the original printing volume (and actually it could gain a couple of cm in the Y direction), and does not need a second motor.
I tried to make the design as simple as possible, without the need to modify anything on the printer other than removing the now unused parts.

Part list:
1 - GT2 timing belt 6mm 852mm
2 - LM10UU linear motion ball bearings
1 - 8mm lead screw rod 395mm long with T8 nut (the original one is shorter but it can be used by