[Draft - Likely Needs Work] Leniency Checker

[Captain-Quack]

This depends on the following pull request to be approved: https://github.com/qbreader/qb-answer-checker/pull/8

This attempts to create a slider that adjusts how strict the answer checker is, such that a leniency value of $n$ allows 1 mistake every $n$ characters.

This is my first time working with the nitty gritty parts of the repo (rather then just adding, like the testing), so some extra eyes would be much appreciated.