DOC: Add links to a few items close to the top of crate docs

Author: bluss

src/lib.rs

@@ -38,8 +38,8 @@
 //! - Higher order operations and arithmetic are performant
 //! - Array views can be used to slice and mutate any `[T]` data using
 //!   `ArrayView::from` and `ArrayViewMut::from`.
-//! - `Zip` for lock step function application across two or more arrays or other
-//!   item producers (`NdProducer` trait).
+//! - [`Zip`](struct.Zip.html) for lock step function application across two or more arrays or other
+//!   item producers ([`NdProducer`](trait.NdProducer.html) trait).
 //!
 //! ## Crate Status
 //!

src/zip/mod.rs

@@ -128,7 +128,8 @@ where
 /// for example an array view, mutable array view or an iterator
 /// that yields chunks.
 ///
-/// Producers are used as a arguments to `Zip` and `azip!()`.
+/// Producers are used as a arguments to [`Zip`](struct.Zip.html) and
+/// [`azip!()`](macro.azip.html).
 ///
 /// # Comparison to `IntoIterator`
 ///