Ender 3 Vent Ring with offset and spacers

Ender 3 vent ring 2 with added options. Added a spacer in the z direction to keep ring offset from bottom of extruder housing. This results in the ring always being level with the print area, even if screws are over tightened. Additionally added spacers that go behind the screws to also prevent over tightening and to give more support to the fan (prevent plastic bending if screws over tightened). I originally tried just spacers from Ender 3 fan washer by Brassee alone but found that they would spin when trying to screw in or out and prevent the screw from advancing. This solves that problem by having them part of the ring and thus unable to spin. Putting in screws is much easier compared to spacers alone.