WP20 Launch

[adamwoodnz]

• [x] Final signoff received
• [x] Pull latest changes in prod
• [x] Enable theme
• [x] Configure theme following README
• [x] Trash initial pages
• [x] Update styles hardcoded in post content to make them compatible with new theme
  • [x] Spotify button text color on 20 Years post (see #78)
• [x] Handover to maintainers