Define the protocol allowing the software to track tags
and program them, in the README.
The data structure is shared between a programming command and an
information message, so create a new struct for it and an array
to keep track of it and expose to the rest of the program.
The goal is to keep the protocol core and message construction
entirely inside Com, so this intermediary buffer allows exposing
it outside while hiding the protocol details.
This means that we are starting to receive data from the software,
so implement generic functions to check and receive data as well
as receiveMessage() which parses the message and handles them.
sendComment cannot send more than 62 bytes, as limited by the HID report.
Sending more is prevented by vsnprintf, but change the function signature
to make it explicit that the array passed to it should be at most 62 bytes.
Implement a set of functions to create messages following the protocols
defined in the README for communication.
Handle HID, which is used to communicate with the interactive application.
Update README with details on the message structures.
