Add rakudo-specificness of "dd", AlexDaniel++

Author: lizmat

doc/Language/faq.pod6

@@ -556,9 +556,9 @@ except the type).
     say $x;         # OUTPUT: «(Date)␤»
 
 If you like to show a debugging version of an object, it is probably better
-to use C<dd>.  It essentially does a C<$obj.perl> and shows that on STDERR
-rather than STDOUT, so it won't interfere with any "normal" output of your
-program.
+to use the L«rakudo-specific C<dd> routine|/programs/01-debugging#Dumper_function_dd».
+It essentially does a C<$obj.perl> and shows that on STDERR rather than STDOUT,
+so it won't interfere with any "normal" output of your program.
 
 So, C<say> is optimized for casual human interpretation, C<dd> is optimized
 for casual debugging output and C<print> and C<put> are more generally suitable