DC42 Mini height sensor board support for e3d v6

This allows DC42's (David Crocker) IR height sensor board to be attached to an E3D v6 hot end sandwiching the new support between the E3D shroud and the 30mm fan supplied by them.
Available in OnShape at: https://cad.onshape.com/documents/5f57ce2757134470f827174b/w/72fc898f0f948db66966b8fe/e/1fff43614fd32072253c43d0

(note the photos show the orientation of the fan shroud to ensure the board sits above the nozzle - cannot persuade the photos to be in the correct sense - sorry!)

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