Motorshield v2.3: connect Vin jumper internally

This is a minor feature request for the Motorshield part.
It does not seem possible to connect wires to the VIN jumper on the Fritzing part. Instead VMOTOR has to be supplied directly to the pad on the screw terminal. It would be nice if the 2-male-pin jumper connector could act as intended, i.e. if it was possible to short it with a wire to internally connect VMOTOR on the screw terminal with VIN.

Start by locating the Fritzing Motorshield v2.3 part definition and inspect how the VIN jumper, VMOTOR, and screw-terminal pad are represented. Update the part so the jumper can internally connect VMOTOR to VIN when shorted, then verify the connector and terminal behave as described in Fritzing.

Written by the indexing model from the issue text.