I built three of these and was confused as to why my numpad 0 wasn't
working. Eventually, I consulted this website to see the key matrix for
the Model M
https://sharktastica.co.uk/sims/matrix?kb=enhanced
`kp_0` is in the matrix at [0, 12], not [0, 11]. Simple off by one
error. I fixed this, flashed to all my keyboards, and it worked.
Co-authored-by: Kay Barkbark <kay@laptop>