Use pre-commit library to run linters

[noloerino]

We currently run pre-commit via a shell script that needs to manually be linked to .git/hooks/pre-commit, but in my experience I've found this to be somewhat unreliable.

I'm not sure if this is due to some versioning or configuration differences, but running black + flake8 + isort on all files in current main leads to hundreds of warnings in my local dev environment, so I edited my own copy of the pre-commit hook to only change files in git diff --name-only. Moreover, it seems like the exit code of a failed black --check does not properly pre-empt a commit on a failed lint, so I frequently have to go back and amend a commit on a failed lint.

We should add pre-commit as a dev dependency to automatically handle lints for us so we don't have to worry about fixing the script.