Add basic hardware documentation

[schneidr]

Could you add a little section to the Readme on how to connect the Mrf24j40MA module to the Pi? I'm familiar with it from an Arduino and most connections are the same, but I can't figure out how to connect the INT and CS pins of the Mrf24j40MA module.

[mstaflex]

Hi. I have not used any interrupt gpio so far. For now, I did mere polling to check if some new packet has arrived. As for the cs line the setup ist rather simple. The SPI module (hardware) used with the python code, controls also the cs line. There are two possible spi devices and also two corresponding cs lines. You can look them up in any gpio header description of the pi.

[mstaflex]

Please check out the blog post I have written about the SPI interface of the pi. http://eleflex.blogspot.de/2013/04/rasppi-spi-with-python.html?m=1
It also includes the pin header description and a basic spi example.