Spell "partitionwise" consistently.
I'm not sure which spelling is better, "partitionwise" or "partition-wise",
but everywhere else we spell it "partitionwise", so be consistent.
Tatsuro Yamada reported the one in README, I found the other one with grep.
Discussion: https://www.postgresql.org/message-id/
d25ebf36-5a6d-8b2c-1ff3-
d6f022a56000@lab.ntt.co.jp