Fix Contributing document format issue

[asteves]

This PR does two things:

1. Closes #519 by updating the markdown to appropriately render as a bulleted list.
2. Closes #518 by updating the contributing.qmd source to show the code blocks as separate code blocks and give the option to copy code blocks via copy-code annotations.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

see 28 files with indirect coverage changes

[s3alfisc]

@all-contributors please add @asteves for docs

Looks great, thank you Alex! =)

[allcontributors[bot]]

@s3alfisc

I've put up a pull request to add @asteves! :tada: