Allow fuzzy search for LocalProvider

[xemle]

First of all: ❤️ Thank you so much for this awesome project! I am loving it. I evaluate it to migrate my sphinx based documentation for my side project HomeGallery to rspress and I gain good progress.

What bugs me is the search result. While rspress uses FlexSearch which comes with create great text search capabilities #matchResultItem skips fuzzy matches by searching the query as query phrase using LocalSearch provider only. E.g. I have a title Extractor Plugin but for the query 'plugin extractor' I receive empty search results. This is very bad for technical documentation site because search terms are spread over the document content and a user should find at least some matches.

By inspecting the code:

    const normalizedTitle = normalizeTextCase(title);
    if (normalizedTitle.includes(query)) {
      // return match
    } else {
      // remove this match
    }

in #matchTitle or

    const normalizedContent = normalizeTextCase(content);
    let queryIndex = normalizedContent.indexOf(query);

in #matchContent only a phrase search match produces a hit.

When having only the local search provider, #matchContent skips the fuzzy search and returns an empty list while FlexSearch provided results:

    if (queryIndex === -1) {
      // In case fuzzy search
      // We get the matched content position from server response
      const highlightItems = (item as RemotePageInfo)._matchesPosition?.content;
      if (!highlightItems?.length) {
        return;
      }
      ...
    }

At the end, PageSearcher.match(keyword, limit) does not offer to hook into the raw result of the search provider (FlexSearch) by returning only the post processed and empty matchResult. Then in SearchPanel.tsx the onSearch hook receives only the filtered result.

So my question is: How can I enable fuzzy search with the FlexSearch as LocalSearch provider so that rspress find matches when the user flips terms? Is this fuzzy search for local provider NIY or not provided on purpose?

For me it would be OK to pass the raw provider result to the onSearch hook so that a custom implementations can post process the result of the provider.

RFC