Add example of nested Q delimiters

Closes #1256

Author: coke

doc/Language/quoting.pod6

@@ -18,6 +18,7 @@ described in more detail in the following sections.
 B<Q[>A literal stringB<]>
 B<｢>More plainly.B<｣>
 B<Q ^>Almost any non-word character can be a delimiter!B<^>
+B<Q ｢｢>Delimiters can be repeated/nested if they are adjacent.B<｣｣>
 
 Delimiters can be nested, but in the plain C<Q> form, backslash escapes
 aren't allowed.  In other words, basic C<Q> strings are as literal as