Fix order of named and positional parameters.

Thanks to David H Adler and James E Keenan in RT #77220

src/subs-n-sigs.pod

@@ -353,7 +353,7 @@ Appending a C<!> makes it mandatory.
 
 =begin programlisting
 
-    sub design-ice-cream-mixture(:$name!, $base = 'Vanilla') {
+    sub design-ice-cream-mixture($base = 'Vanilla', :$name!) {
         say "Creating a new recipe named $name!"
     }