document antipairs for Setty,reorder in page

doc/Type/Setty.pod6

@@ -97,28 +97,28 @@ die face is a set element.
 
 If C<*> is passed as C<$count>, the list is infinite.
 
-=head2 method keys
+=head2 method antipairs
 
 Defined as:
 
-    multi method keys(Setty:D: --> Seq:D)
+    multi method antipairs(Setty:D: --> Seq:D)
 
-Returns a L<Seq|/type/Seq> of all elements of the set.
+Returns all elements in the set and C<True> as a L<Seq|/type/Seq> of L<Pairs|/type/Pair>,
+where the element itself is the value, i.e. the opposite of method C<pairs>.
 
-    my $s = Set.new(1, 2, 3);
-    say $s.keys;                                      # OUTPUT: «(3 1 2)␤»
+    my $s = Set.new(1, 2, 3, 1);
+    say $s.antipairs.sort;                            # OUTPUT: «(True => 1 True => 2 True => 3)␤»
 
-=head2 method antipairs
+=head2 method keys
 
 Defined as:
 
-    method antipairs(Setty:D: --> Seq:D)
+    multi method keys(Setty:D: --> Seq:D)
 
-Returns all elements in the set and C<True> as a L<Seq|/type/Seq> of L<Pairs|/type/Pair>,
-where the element itself is the value, i.e. the opposite of method C<pairs>.
+Returns a L<Seq|/type/Seq> of all elements of the set.
 
-    my $s = Set.new(1, 2, 3, 1);
-    say $s.antipairs.sort;                            # OUTPUT: «(True => 1 True => 2 True => 3)␤»
+    my $s = Set.new(1, 2, 3);
+    say $s.keys;                                      # OUTPUT: «(3 1 2)␤»
 
 =head2 method values