DigitalOcean and Github for the last few years have put together an
event called "Hactoberfest" where you can sign up and get a shirt after
5 pull requests.

I've made a repo to build out tests for all of ServiceNow's tool to help
everyone get there.

Check it out on Github.

To contribute you just need a personal developer instance and the drive
to make a test and / or suite to test some OOB functionality.

All tests should be self contained. What do I mean by that? Well,
anything you reference in the test may need to be created like the user
you want to impersonate, and their group memberships/roles.

I do intend on making a custom test as part of this to make the
generation of these artifacts easier but I am still learning how the
code works for those tests.
However this
post

at least is a decent example of someone doing a custom test step.