time_circuit: add level-shifter symbol
time_circuit: add powerconverter board schematic
time_circuit: add DIP-12-400 footprint
time_circuit: add HEADER26_SHROUD footprint
time_circuit: update power converter boards
time_circuit: add makefile to clean out files
time_circuit: add USB-A footprint
time_circuit: add usba symbol
time_circuit: validate levelshifter symbol
time_circuit: add hand-crafted netlist
time_circuit: update powerconverter board
time_circuit: add power jack footprint
time_circuit: add smaller version of VMW logo
time_circuit: final version of the powerconverter board

make it use USB as the power-out connector