WIP - Add fusejs as a search engine for the docs

[rcap107]

This PR is adding Fusejs as a search engine for the documentation. This adds different sections to the search results, and better fuzzy search of the content:

For the moment, this is a proof of concept of what can be done with the search library. This is also mostly vibe-coded, so I need to review everything before we consider merging this in main.

Other things that need to be looked at:

• Testing this over multiple browsers to make sure things don't break elsewhere
• The way chunking is done may be improved
• Doctests probably shouldn't appear in the results of the search
• There are some duplicate results