Update doc/go1.18.html

Author: CAFxX

doc/go1.18.html

@@ -373,7 +373,7 @@ <h3 id="minor_library_changes">Minor changes to the library</h3>
 
     <p><!-- https://golang.org/cl/323318 https://golang.org/cl/332771 -->
       <a href="/pkg/strings/#Trim"><code>Trim</code></a>, <a href="/pkg/strings/#TrimLeft"><code>TrimLeft</code></a>,
-      and <a href="/pkg/strings/#TrimRight"><code>TrimRight</code></a> are up to 5 times faster (especially for
+      and <a href="/pkg/strings/#TrimRight"><code>TrimRight</code></a> are up to 10 times faster (especially for
       small ASCII cutsets) and are now allocation-free.
     </p>