Prusa Mini X-carriage for v6 conversions

My mod for the part cooling fan duct for v6 conversions.
The duct has a swirl lip on the top edge to direct the air around the v6 heat block to the nozzle tip without physically intruding into the print space.

This is a remix of the Original Prusa Design found at
https://github.com/prusa3d/Original-Prusa-MINI/tree/master/STL