Feature/precommit codespell

[milesOIST]

New pre-commit spell checker function.
Developer description: "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."
https://github.com/codespell-project/codespell

Implementation:

Checks new git commits for spelling errors. User cannot submit if there are errors.
Ignored directories: frontend/build frontend/node_modules
Ignored files: *.lock, *.log, *.egg-info
Additional ignored words stored in: .codespellignore
Please add words to .codespellignore if they are incorrectly flagged in your code

[ReiHashimoto]

Sorry, my order was misleading.

pre-commit aim to ensure pushed files have no typo. (for the future)
but currently there already are typos, so pls fix them in this PR using codespell, too.

[ReiHashimoto]

Pls fix these problems, too.

[ReiHashimoto]

LGTM