docs: generate sitemaps + change search filters (#8957)

- Generate sitemaps for `book` and `resources` projects (in attempt to resolve some pages not being picked up by the crawler)
- Change the v2 search filters

> Note: will require changes to algolia's crawler + a recrawl once merged

www/packages/build-scripts/src/index.ts

@@ -1,5 +1,6 @@
 export * from "./generate-edited-dates.js"
 export * from "./generate-sidebar.js"
+export * from "./retrieve-mdx-pages.js"
 
 export * from "./utils/find-metadata-title.js"
 export * from "./utils/find-page-heading.js"