re-organise how flashing instructions are stored

[rcooke-warwick]

its not strictly a USB-> something conversion, it uses the autokit to achieve something else - which are arguements for it (both the methods to flash + the per device type instructions) to be moved somewhere else

[rcooke-warwick]

there is duplication in flashing instructions across this repo, device type contracts and os repo coffee files
Additionally, we don't want to add a device type for every device to the autokit repo

[rcooke-warwick]

one proposal was to replace all device type json files in this repo with "generic" flashing instructions - and then pull the "flashing type" from the coffee file in the os device type repository.

That way instead of saying something like "intel nuc requires this flashing procedure" both here, and there - we can do it only once there