Misc. UX and UI enhancements

[zmre]

• Setup for perf enhancements to pagefind
  • Locally they speed up indexing by over 2x, but we need to wait for the PR
• Make client-side enrichment lazy load (and not load when not needed)
• Make a mbr-cli target that doesn't build mac apps for use as a nix dependency in certain situations
• Generate enhanced boxes for oembed opengraph fetches
• Add styling for footnotes
• Add styling for printing
• Update dependencies
• Add build progress on static builds
• Make markdown docs link to info about each markdown extension if not our extensions