rustdoc search: allow combining a type based search with a name based search

[lolbinarycat]

usecase: i know reqwest has a method on Response that turns error status codes into Result. i know it probably has "error" in the name. it would be nice to be able to do something like "error" Response -> Result to search for this.

in this case, just Response -> Result works well enough, but that seems to be a coincidince due to async functions being ranked below sync functions.