Add information about board designs/wiring/firmware to github

Let's try and make this a comprehensive repository of the information required to implement the dance floor :)

[fraz3alpha]

The final firmware was closely modelled on the code available from solderlab.de - http://solderlab.de/index.php/hardware/matrix-controller-board , and follows the same key circuit connections between the ATMega328 and TLC5940 LED drivers. This code had all the interrupts and config already coded up, so it seemed silly to write it all again just for the hell of it.

The woodwork was largely nailed down (no pun intended) before the cutting started, and I can readily compile a complete list of what bits were required, and where we got it from, possibly including how much it cost (another interesting breakdown to consider tallying up). Wickes was the source, and I needed to borrow Simon's tablesaw to cut all the MDF down.

Polycarbonate was 6 sheets of 9' x 3'3" from a man near MK on gumtree, £25 a sheet, cut down to 915mm x 1220mm (3'x4')

LEDs, en-masse from eBay, together with ping pong balls, TLC5940 driver ICs, ATMega328's, heatshrink, female connectors
Rapid Electronics provided stripboard, nearly 1km of wire, safety equipment for cutting MDF
Tesco provided the foil
Toolstation had rolls of masking tape (I think we used close to 15 @ 25m each), screws, bolts,
My boxes of bits provided the other required PCB components: resistors, capacitors, screw terminals (and a few borrowed from Steve)