Quarto FollowUp

[epinzur]

Make Ben's requested changes from PR #799

[epinzur]

• Consider improving the CI flow
• Add an _extensions README.md
• Move Slack-Join URL to a variable (not possible)
• Attempt to move index text to separate files
• Add a _scripts README.md
• Re-add comments to the bluesky example
• Convert the reddit example to qmd
• Adjust spacing of docstrings for aliases
• Create Issue/PR to on include-code-files extension to support start & end tags
• Add a comment to the commented-out fields
• Refactor the card template to not require design-styles.css
• Move announcement text to a variable