docs: Rewrap str::strip_prefix and strip_suffix back to 100

Requested-by: @LukasKalbertodt
Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

Author: ijackson

library/core/src/str/mod.rs

@@ -1964,10 +1964,8 @@ impl str {
 
     /// Returns a string slice with the prefix removed.
     ///
-    /// If the string starts with the pattern `prefix`, returns
-    /// substring after the prefix, wrapped in `Some`.
-    /// Unlike `trim_start_matches`, this method removes the
-    /// prefix exactly once.
+    /// If the string starts with the pattern `prefix`, returns substring after the prefix, wrapped
+    /// in `Some`.  Unlike `trim_start_matches`, this method removes the prefix exactly once.
     ///
     /// If the string does not start with `prefix`, returns `None`.
     ///
@@ -1993,10 +1991,8 @@ impl str {
 
     /// Returns a string slice with the suffix removed.
     ///
-    /// If the string ends with the pattern `suffix`, returns the
-    /// substring before the suffix, wrapped in `Some`.
-    /// Unlike `trim_end_matches`, this method removes the
-    /// suffix exactly once.
+    /// If the string ends with the pattern `suffix`, returns the substring before the suffix,
+    /// wrapped in `Some`.  Unlike `trim_end_matches`, this method removes the suffix exactly once.
     ///
     /// If the string does not end with `suffix`, returns `None`.
     ///