Exam Key Generator

[ClarissaMilligan]

Originally posted by @ReeseHatfield in #151

@ClarissaMilligan and I have been talking about enhancing the typst exam generation code to be able to auto generate keys. This would require require passing more than just the answer strings as the sink. Pass something [String: answer, Bool: isCorrect]. As well as indicate whether or not the key should be generated

      --input <key=value>
          Add a string key-value pair visible through `sys.inputs`

Nevermind, aparently they do, just a little roundabout way

Something like
https://www.reddit.com/r/typst/comments/1dhttk2/compile_chapters_based_on_inputkey/