Add typo check in CI

[GuillaumeGomez]

Things to be careful about (comment from here):

There's a ton of false positives, like converting "lits" (literals) to "list". The tools actually wants to fix the mock Latin in lorem ipsums. I don't know how much of a hassle it would be to set it up right. In most cases "lits" is a typo, just in in one case it isn't.