Rework sitemaps to provide more coverage of the site. We want every
important page on the site - including every post, tag, and wiki page -
to be indexed by Google. We do this by generating sitemaps and sitemap
indexes that contain links to every important page on the site.
/packs was blocked by robots.txt, which prevented Googlebot from
fetching CSS when indexing pages, which made Google penalize pages for
being mobile unfriendly because it couldn't load the CSS and it thought
the layout was broken.
