TODO: fix ci/cd

[RooRay]

Currently, commitlint and the spell check run twice on a pull request (although GitHub is smart and skips the second spellcheck since it already runs on pushes)

Consider rewriting the workflow files to only run on push, or on a pull request. Alternatively, fix their current behaviour so they run once on commit and once in a pull request (so they can be required to pass in order to merge a pull request)

above is fixed, although it would be nice to show all 3 checks on commits to main, oh well

Also add a contributing guide with a warning that only british english is supported (and mentioning that work is done on dev branch due to protection rules)