Row 13 would have been an overflow error somewhere
(should be in the range 0-12).
Now matches the keyboard.json values.
So two chances to spot this error at compile time missed.
This is more functional than the QMK bare-bones default, although why
the HRM on the right are not all right-modifiers escapes me. This is
important where right-alt AKA AltGr is used for accents etc.
It was e for edge, now k for keys. Why? I'm toying with ideas
for a full Tutte Coxeter graph (30 vertices/nodes/GPIO pins,
45 edges/switches) incuding 42 keys plus a rotary encoder
(these act like three switches: clockwise, anticlockwise,
press - so 42 edges for normal keys + 3 edges for a rotary
encoder gives 42 + 3 = 45 edges) which could be named with
suffix 43ke.
