link to arity

Author: gfldex

doc/Language/functions.pod6

@@ -212,7 +212,7 @@ each candidate with the C<multi> declarator.
     congratulate 'Larry';       # Happy birthday, Larry
     congratulate 'Bob', 45;     # Happy 45th birthday, Bob
 
-Dispatch can happen on the number of arguments (the I<arity>), but also on the
+Dispatch can happen on the number of arguments (the L<arity|/type/Routine#(Code)_method_arity>), but also on the
 type:
 
     multi as-json(Bool $d) { $d ?? 'true' !! 'false'; }