change struct description to pred.normalize() for consistency

Author: kammitama5

src/str/normalize.rs

@@ -15,7 +15,7 @@ use std::iter::FromIterator;
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 /// Predicate adapter that normalizes the newlines contained in the variable being tested.
 ///
-/// This is created by `pred.normalized()`.
+/// This is created by `pred.normalize()`.
 pub struct NormalizedPredicate<P>
 where
     P: Predicate<str>,