Add <p> element to label the new ordered list.

- Improve consistency of challenge seeds
- Clarify challenge objective for "Waypoint: Created an ordered list"

challenges/basic-html5-and-css.json

@@ -1527,7 +1527,8 @@
         "  <li>cat nip</li>",
         "  <li>laser pointers</li>",
         "  <li>lasagna</li>",
-        "</ul>"
+        "</ul>",
+        "<p>Top 3 things cats hate:</p>"
       ],
       "challengeType": 0,
       "nameCn": "",