use a better sub name

Author: tbrowder

doc/Language/mop.pod6

@@ -16,11 +16,11 @@ For example:
 
 =begin code
 my $arr = [1, 2];
-sub foo($arr) {
+sub show-type($arr) {
     my $typ = $arr.WHAT.^name;
     say $typ;
 }
-foo $arr; # OUTPUT: «Array␤»
+show-type $arr; # OUTPUT: «Array␤»
 =end code
 
 To get a more in-depth understanding of the meta object for a C<class>, here is an example