PRs

If you want to contribute code or a test or to the book:

if no existing issue exists for it, create one so we can agree on what to do before starting (a good idea to make later PR merges easier to accept I think!)
if an issue exists already add a comment to it so I know you want to work on it
fork the repo
create a branch for the issue in your repo
make your changes and update tests, code docs, the book and examples as required
run local build and test ('make') before pushing to your branch
wait for GH Actions on PR to pass
submit the PR, referencing the issue is a good idea