Adds the coherent part of the dynamics — the Hamiltonian superoperator H, covering the Zeeman
interaction (including chemical shift) and J-coupling — and combines it with the existing
relaxation superoperator R into the full Liouvillian L = −i[H, ·] − R, the
generator of the complete equation of motion. Accompanied by a package reorganisation and general
updates.
See the README for full details.