Mention current designs in name badge ticket

We don't need to design them every year. The current designs are great.

Author: RealOrangeOne

comp/volunteers/name-badges.yaml

@@ -9,3 +9,5 @@ milestone: $SRYYYY Competition
 description: >-
     Name badges should be printed for all volunteers we know will be there.  We
     should also have blank badges for those we don't expect.
+
+    See https://github.com/srobo/promotional-material/tree/master/name-badges for the current designs.