Document arbitrary and quickcheck features

Author: rjsberry

src/arbitrary.rs

@@ -1,4 +1,5 @@
 #[cfg(feature = "arbitrary")]
+#[cfg_attr(docsrs, doc(cfg(feature = "arbitrary")))]
 mod impl_arbitrary {
     use crate::{IndexMap, IndexSet};
     use arbitrary::{Arbitrary, Result, Unstructured};
@@ -35,6 +36,7 @@ mod impl_arbitrary {
 }
 
 #[cfg(feature = "quickcheck")]
+#[cfg_attr(docsrs, doc(cfg(feature = "quickcheck")))]
 mod impl_quickcheck {
     use crate::{IndexMap, IndexSet};
     use alloc::boxed::Box;

src/lib.rs

@@ -40,13 +40,19 @@
 //!   to [`IndexMap`] and [`IndexSet`]. Alternative implementations for
 //!   (de)serializing [`IndexMap`] as an ordered sequence are available in the
 //!   [`map::serde_seq`] module.
+//! * `arbitrary`: Adds implementations for the [`arbitrary::Arbitrary`] trait
+//!   to [`IndexMap`] and [`IndexSet`].
+//! * `quickcheck`: Adds implementations for the [`quickcheck::Arbitrary`] trait
+//!   to [`IndexMap`] and [`IndexSet`].
 //!
 //! _Note: only the `std` feature is enabled by default._
 //!
 //! [feature flags]: https://doc.rust-lang.org/cargo/reference/manifest.html#the-features-section
 //! [`no_std`]: #no-standard-library-targets
 //! [`Serialize`]: `::serde::Serialize`
 //! [`Deserialize`]: `::serde::Deserialize`
+//! [`arbitrary::Arbitrary`]: `::arbitrary::Arbitrary`
+//! [`quickcheck::Arbitrary`]: `::quickcheck::Arbitrary`
 //!
 //! ### Alternate Hashers
 //!