Documentation: contributors guide too vague

[hkershaw-brown]

What's the issue?

📚 Please describe the problem you’ve noticed in the documentation.

The contributors guide is quite vague about how to contribute to dart.
And it is not super friendly, e.g. find a documentation problem, contribute a fix!

Where did you find the issue?

Provide the location(s) of the issue:

• File name or URL: https://docs.dart.ucar.edu/en/latest/guide/contributors-guide.html
• Section name or header: Contributors’ guide

What needs to be fixed?

Share what’s incorrect, unclear, missing, or outdated.

Missing Practicalities of git & github:

• branching of main
• keeping your branch up to date
• exact commands to do this
• what we expect, e.g what to test, what info to provide
• what we look for in review
• basic style guide

There is some typos/weird grammar in there also.

I don't think this is true in general without funding: "DAReS staff can collaborate with you on your private repository,"

Suggestions for improvement

If you have any ideas to fix or generally improve this documentation, please share them.
Make more welcoming,
Clear steps for contributing

Anything else we should know?

Include any other relevant details, such as references, screenshots, or related discussions.
Metpy's contributing guide is quite nice:
https://unidata.github.io/MetPy/latest/devel/CONTRIBUTING.html