Initial version of deployment guide

Addresses #304 

What else do we want in here?
@zenhack @gsilvis 
Perhaps:

Firmware updates for the motherboard and for peripheral devices should be disabled via hardware (ideally) or software mechanisms, as they could represent a vector by which a user (whether maliciously or unintentionally) could impact future users of a machine and possibly violate their security. It is important to note that administrators should also monitor the manufacturers' websites for legitimate firmware upgrades and update nodes themselves, as these could contain security or other fixes.  Here is an incomplete list of peripherals for which this is particularly important: