Don't re-export everything from buf module

src/buf/mod.rs

@@ -1,3 +1,21 @@
+//! Utilities for working with buffers.
+//!
+//! A buffer is any structure that contains a sequence of bytes. The bytes may
+//! or may not be stored in contiguous memory. This module contains traits used
+//! to abstract over buffers as well as utilities for working with buffer types.
+//!
+//! # `Buf`, `BufMut`
+//!
+//! These are the two foundational traits for abstractly working with buffers.
+//! They can be thought as iterators for byte structures. They offer additional
+//! performance over `Iterator` by providing an API optimized for byte slices.
+//!
+//! See [`Buf`] and [`BufMut`] for more details.
+//!
+//! [rope]: https://en.wikipedia.org/wiki/Rope_(data_structure)
+//! [`Buf`]: trait.Buf.html
+//! [`BufMut`]: trait.BufMut.html
+
 use std::{cmp, io, usize};
 
 mod buf;