Better documentation for quirks module

[brson]

The description is "Getters and setters for URL components implemented per https://url.spec.whatwg.org/#api", which seems like a reasonable thing, and then the next sentence is a strong warning not to use this module. A clearer lay-description of what this module is would be helpful.

[SimonSapin]

This module belong in Servo. It is only in the url crate because it uses internal things that don’t necessarily make sense to stabilize in the public API.

[untitaker]

You could define a "unstable" feature for rust-url that reexports those private APIs.

EDIT: Or hide the quirks module behind a feature flag so people usually don't encounter it.

[SimonSapin]

There is a fairly strong convention that "unstable" means "uses unstable features of the Rust language or standard library, requires a Nightly compiler".

And making this module not compiled by default is technically a breaking change.

[dtolnay]

If this module does not belong in the url crate, how about:

// This module is for Servo. Do not use this module outside of Servo.
#[doc(hidden)]
pub mod quirks;

Or possibly, if Servo developers need to be able to see the docs:

// This module is for Servo. Do not use this module outside of Servo.
#[cfg_attr(not(feature = "quirks"), doc(hidden))]
pub mod quirks;

[SimonSapin]

I took your suggestion @dtolnay, thanks.