Minor comment cleanups.

lib/cretonne/src/bitset.rs

@@ -1,10 +1,10 @@
 //! Small Bitset
 //!
-//! This module defines a struct BitSet<T> encapsulating a bitset built over the type T.
+//! This module defines a struct `BitSet<T>` encapsulating a bitset built over the type T.
 //! T is intended to be a primitive unsigned type. Currently it can be any type between u8 and u32
 //!
 //! If you would like to add support for larger bitsets in the future, you need to change the trait
-//! bound Into<u32> and the u32 in the implementation of max_bits()
+//! bound Into<u32> and the u32 in the implementation of `max_bits()`.
 use std::mem::size_of;
 use std::ops::{Shl, BitOr, Sub, Add};
 use std::convert::{Into, From};