Add an example for multi method comb(Str:D :)

Author: titsuki

doc/Type/Str.pod6

@@ -262,6 +262,7 @@ If no matcher is supplied, a list of characters in the string
 
 Examples:
 
+    say "abc".comb.perl;                 # ("a", "b", "c").Seq
     say comb(/\w/, "a;b;c").perl;        # ("a", "b", "c").Seq
     say comb(/\N/, "a;b;c").perl;        # ("a", ";", "b", ";", "c").Seq
     say comb(/\w/, "a;b;c", 2).perl;     # ("a", "b").Seq