Updating pre-commit

[davidorme]

This PR is simply to update the pre-commit settings to try and fix issues reported by @arne-exe in #123.

• It also removes a linting check for code complexity, which is no longer a standard part of the linter checking - and probably isn't a priority for R scripts (as opposed to package and function level complexity).
• It fixes a new markdown issue revealed by pre-commit run -a

[jacobcook1995]

LGTM!