Adjust margins for paperback version. Ensure nothing breaches the right margin.

book/src/04_traits/04_derive.md

@@ -89,7 +89,8 @@ although a bit more cumbersome to read:
 impl ::core::cmp::PartialEq for Ticket {
     #[inline]
     fn eq(&self, other: &Ticket) -> bool {
-        self.title == other.title && self.description == other.description
+        self.title == other.title 
+            && self.description == other.description
             && self.status == other.status
     }
 }

book/src/04_traits/05_trait_bounds.md

@@ -99,7 +99,8 @@ error[E0599]: no method named `is_even` found for type parameter `T`
  --> src/lib.rs:2:10
   |
 1 | fn print_if_even<T>(n: T) {
-  |                  - method `is_even` not found for this type parameter
+  |                  - method `is_even` not found 
+  |                    for this type parameter
 2 |     if n.is_even() {
   |          ^^^^^^^ method not found in `T`