Add possible search implementation

[CoderMuffin]

Add a possible implementation for searching.

Potential issues:

• Can't reorder search terms - they must appear in the same order as the document
• Search may be a little too permissive in some cases (allows partial matches of 3+ characters in the middle of words)
• Search performance is a little slow for long queries

[rsa33]

Ok, this builds and seems to work -- the matching is a little funky (e.g. typing an extra character sometimes produces more results rather than narrowing) but generally surfaces useful pages, which I think is a huge improvement over a lack of search.

The latency on long queries is a bit rough though. Whilst I'd expect most people not to write too much here, pasting errors and the like may make it noticeable. A quick look around online led me to flexsearch and its benchmark page which suggests fuse might be one of the slowest libraries. 😅 Is it worth trying a different one?

[CoderMuffin]

might be able to remove these? can't seem to get a meaningful difference in results with/without them - I think suggest: true might cover the same case