QG8 file specification and programmers reference v1.0

First release of the QG8 exchange file format.

QG8 is a lightweight format for storing and exchanging numerical tensor data and data flow graphs in a binary format. It was created as way to store quantum models and data in a single file, including quantum gate and quantum circuit specifications, control pulse definitions, time independent and time-dependent model Hamiltonians, device characteristics, calibration data and noise models, user defined control flow instructions and simulation or measurement results. This facilitates numerical simulation and optimization of quantum problems as well as interfacing with quantum computers.