47411ce73d Fix typo in documentation (Tobin Harding)
Pull request description:
Docs reference a function name but there is a typo.
'grund' -> 'grind'.
ACKs for top commit:
apoelstra:
ACK 47411ce73d
Tree-SHA512: e6724f1c7972625d59be0ae9de358295c9280e2e126e7322d706cbdca342c1189552b2fdeef9370ff4f85ea8ef185ef4447f6693979d5e8548fcfa2df41a491e