Add note about Tradeverifyd.

Author: BigBlueHat

abstract.hbs

@@ -4,4 +4,10 @@
   for <a href="https://w3c.github.io/vc-bitstring-status-list/">Bitstring Status
   List</a>.
   </p>
+  <p>
+    In addition to the test results below,
+    <a href="https://github.com/w3c/vc-bitstring-status-list-test-suite/issues/61">Tradeverifyd has claimed</a>
+    to have successfully implemented every feature, including the ability to
+    host multiple statuses in a single list.
+  </p>
 </section>