Migrate the blog out of Drupal and into a static site generator with a comment service

Content

• Import blog posts from Drupal
• Import events from Drupal
• Import comment archive
• Configure RSS/Atom feeds (posts + events)
• Implement categories to replace tags (depends on #40008 (closed))
• Test Discourse comments embedding (depends on tpo/tpa/team#40183 (closed))
• Test draft post feature

Layout

• Import relevant CSS styles from old blog
• Setup 2-column responsive layout
• Mirror header and footer contents from other Tor websites

Deployment

• Ensure functioning newsletter image URL redirections (example)
• Plan/implement publishing moratorium and comments section closure on Drupal
• Full, final content import from Drupal
• Setup static web mirrors for new site
• Transition blog.torproject.org address
• Fossilize old Drupal site (#40011 (closed))
• Wind down Pantheon subscription (tpo/tpa/team#40526 (closed))
• Retire (or reconfigure) cache*.torproject.org machines (tpo/tpa/team#40527 (closed))

Workflow

• Implement Review Apps for easy MR previews
• Document final publishing workflow of the new blog

Documentation of the project requirements lives at https://gitlab.torproject.org/tpo/tpa/team/-/wikis/service/blog