Minkowski bases for 12et

These don't seem to vary widely, which makes sense.

JI: 81/80, 128/125 syndie
36/35: 81/80, 128/125 syndie
50/49: 128/125, 81/80 syndie
64/63: 81/80, 2048/2025 syndia
3125/3087: 128/125, 81/80 syndie
126/125: 128/125, 648/625 thirds
4000/3969: 81/80, 128/125 syndie
225/224: 2048/2025, 128/125 diadie
3136/3125: 128/125, 81/80 syndie
5120/5103: 81/80, 2048/2025 syndia