Use MyST as the markup format

[bryanwweber]

The MyST markup format is a combination of the best parts of Markdown and RestructuredText. It can be installed as a Sphinx extension, so upon completion of #209 we shouldn't have much trouble to add this as a dependency. I think tackling this issue is best done after completing #210, to avoid conflicts with any content changes needed for that issue.

We should consider using MyST-NB so that the documentation pages (especially the tutorials) can be executed at build time. Content can still be written as Markdown files, but code markup sections become executable, which would be useful to smoke out errors in content due to API changes, etc.

Action Items

• Add dependency on the MyST parser extension
• Update Sphinx configuration to use this extension
• Use sphinx-design for native Bootstrap theme support (ADDED 18-JUN-2022, please pull the updated branch 😄)
• Convert all prose content (tutorials, science, etc.) to use MyST markup

Non-Goals

• Significant modifications or restructuring of content. This issue should focus on converting existing content to MyST format, not on adding, extending, modifying, or restructuring content.