Re-enable contextual search

[lrettig]

I disabled contextual search in 7705428 to get search working. I believe it wasn't working due to this issue: https://discourse.algolia.com/t/algolia-searchbar-is-not-working-with-docusaurus-v2/14659/. I made sure the attributesForFaceting settings were correct on the algolia crawler side, this didn't help. Let's leave it off for now and revisit in future.

See also: https://stackoverflow.com/questions/72838375/algolia-docsearch-in-docusaurus-doesnt-bring-any-results, https://docusaurus.io/docs/search