Add image thumbnail and website description (from Twitter bio) for the landing page so it appears in Twitter Cards/Facebook messages/posts when shared. Facebook called this "Sandcastle."
Related Linear issues with full context: [[ https://linear.app/comm/issue/ENG-1066/add-image-thumbnailwebsite-description-for-landing-page-when-shared | ENG-1066 ]] and [[ https://linear.app/comm/issue/ENG-889/investigate-deploy-previews-for-web-and-landing | ENG-889 ]].