Document custom crate path

Author: stephaneyfx

enum-iterator/src/lib.rs

@@ -53,6 +53,18 @@
 //! assert_eq!(last::<Foo>(), Some(Foo { a: true, b: 255 }));
 //! ```
 //!
+//! # Custom crate path in generated code
+//!
+//! The code generated by the derive macro defaults to using `::enum_iterator` as the path for
+//! items defined in this crate. This can be customized using the
+//! `#[enum_iterator(crate = foo::bar)]` derive macro attribute.
+//!
+//! ```
+//! #[derive(enum_iterator::Sequence)]
+//! #[enum_iterator(crate = enum_iterator)]
+//! struct Foo;
+//! ```
+//!
 //! # Rust version
 //! This crate tracks stable Rust. Minor releases may require a newer Rust version. Patch releases
 //! must not require a newer Rust version.