Extend parsable-R hook to include Quarto notebooks

[athowes]

I saw that PR https://github.com/lorenzwalthert/precommit/pull/325/files added .Rmd files to the parsable-R hook. I wonder if a similar PR could add .qmd also using knitr::purl or similar that works with Quarto.

[lorenzwalthert]

PRs welcome.