"Soften" contributor requirements like unit tests

[mfisher87]

Some contributing requirements may be intimidating users from contributing. Let's change our language in the contributing guide to indicate:

If you're not comfortable writing unit tests, we still welcome your contribution! Just please ask for help and someone from the community will do their best to work with you.

[doug-newman-nasa]

As long as we don't merge any bug fixes/features without tests I'm OK with that.

[jhkennedy]

Yeah, I like saying it's okay to let PR CI/CD run the unit tests instead of needing to do it locally and it's okay to ask for help to make them pass

[mfisher87]

As long as we don't merge any bug fixes/features without tests I'm OK with that.

💯

[mfisher87]

I think a PR template is a good way to communicate the exact checklist in an accessible way, including the "ask for help" part. Then we can shorten the contributing doc a bit by linking to the PR checklist.