Fix typo in crate docs (#107)

src/lib.rs

@@ -6,8 +6,8 @@
 //! This crate provides SIMD-compatible data types.
 //!
 //! When possible, explicit SIMD is used with all the math operations here. As a
-//! fallback, the fact the fact that all the lengths of a fixed length array are
-//! doing the same thing will often make LLVM notice that it should use SIMD
+//! fallback, the fact that all the lengths of a fixed length array are doing
+//! the same thing will often make LLVM notice that it should use SIMD
 //! instructions to complete the task. In the worst case, the code just becomes
 //! totally scalar (though the math is still correct, at least).
 //!