Adding comment for code clarification (#7856)

Co-authored-by: Derek Bailey <derekbailey@google.com>

dart/test/monster_test.fbs

@@ -59,6 +59,8 @@ struct Vec3 (force_align: 8) {
   test3:Test;
 }
 
+// Stats for monster
+
 struct Ability {
   id:uint(key);
   distance:uint;