Add an initial design for a circuit board.

This board is designed for the 2x2 inch acrylic top and bottom case.

It would work, but is not the one getting made.  It needs to be laid
out again to put a CR2032 holder underneath, and move the vibration
sensor further inside so it is protected from prying fingers.

Signed-off-by: Russell Steicke <russells@adelie.cx>
Add a second design for a circuit board.

This one would also work, and is a better design than the first.  It
includes the battery holder soldered underneath the board.

But the circuit has been altered since work was started, and new
components are needed.  A momentary switch and a pull up resistor have
been added so a roll can be made without tapping (press the switch
instead), and another switch has been aded to disconnect the vibration
sensor.

Signed-off-by: Russell Steicke <russells@adelie.cx>
A better board. This one was submitted to pcbzone.

These changes were made to the design:

- A pull up switch to make the die "roll" (in addition to tapping).

- A switch to disconnect the piezo sensor so that taps don't work.
  This is for travel so the die is not continuously activated.

This commit includes tapdie.zip, which is the file submitted to
pcbzone for manufacture.

Some minor changes were made to tapdie.net to improve the layout, so
the netlist does not exactly match the gschem file.

Signed-off-by: Russell Steicke <russells@adelie.cx>