codespell

Fix common misspellings in text files.
It's designed primarily for checking misspelled words in source code (backslash escapes are skipped), but it can be used with other files as well.
It does not check for word membership in a complete dictionary, but instead looks for a set of common misspellings.
Therefore it should catch errors like "adn", but it will not catch "adnasdfasdf".
This also means it shouldn't generate false-positives when you use a niche term it doesn't know about.