Basic edits of CONTRIBUTING.md #8116
Description
Summary
As part of the doc audit process, perform comprehensive review and edit of CONTRIBUTING.md.
Acceptance criteria
- Hyphenate "open source" wherever it precedes a noun.
- Make minor changes to punctuation as necessary.
- Update hyperlinks as needed.
- Ensure that lists are preceded by a sentence ending in a colon.
- Put terms to be defined in quotes, and definitions should be italicized.
- Use directives instead of "please."
- Perform miscellaneous edits to language, punctuation, and organization as needed.