Document type-based search

[jyn514]

I find this really useful, but it's very difficult to find information on it anywhere.

Example of type-based search: https://users.rust-lang.org/t/a-year-in-rust-and-i-still-cant-read-the-docs/46872/20

[jyn514]

This would be a good first issue. The documentation should go somewhere in https://github.com/rust-lang/rust/tree/master/src/doc/rustdoc/src.

[ThePuzzlemaker]

@rustbot claim

[ThePuzzlemaker]

I'll look into any other obscure search features like this, and be sure to document them. (I'll be sure to document at least this one)

[ThePuzzlemaker]

@jyn514 I've actually found that this feature is documented in the "Search Tricks" section of the help dialog.

[ThePuzzlemaker]

And I don't find that it would really be helpful to document this in the rustdoc book as it's more of an emitted feature rather than a rustdoc feature itself. If it wasn't added to the search tricks already, I would add it there.
@rustbot release-assignment

[ThePuzzlemaker]

I feel that the help dialog is already easy to find enough, though the for more options... might be disambiguated to for help... or something like that.

[jyn514]

Hmm that does seem simple enough but I never found it after a year in rust ... cc @rust-lang/rustdoc, does anyone have ideas how to make this more discoverable?

[GuillaumeGomez]

It's true that it's hard to find it, maybe we should add a ? button that would also show the popup alongside the search input?