[Suggestion] Add Contribution Options

[samuel-allan]

I cannot currently see a Contributing.md file or any guidelines, and would very much appreciate if these were added! Another potentially good idea might be to document early stage issues (even if nobody ends up working on them except repository maintainers). Personally I am very interested in contributing to this project

[schasins]

We'd love to have more contributors! Is there a particular feature or issue you'd like to tackle or that motivated you to reach out? We're actually currently working on figuring out the biggest usability issues, prioritizing them, and turning the top priorities into issues. But in the meantime, if you have something you'd like to see added, we'd love to get you involved!

[schasins]

In the meantime, I sketched in some contribution guidelines. Let me know if you have suggestions!