Add average column to results table

wwwroot/js/ui.js

@@ -225,6 +225,7 @@ export function renderResults() {
         <th>${t("results.rank")}</th>
         <th>${t("results.game")}</th>
         <th>${t("results.author")}</th>
+        <th>${t("results.average")}</th>
         <th>${t("results.votesList")}</th>
         <th>${t("results.myVote")}</th>
         <th>${t("results.links")}</th>
@@ -248,6 +249,7 @@ export function renderResults() {
          </div>
       </td>
       <td class="author-cell">${r.author ?? "—"}</td>
+      <td>${r.average?.toFixed ? r.average.toFixed(1) : r.average}</td>
       <td>${formatVotes(r.votes)}</td>
       <td>${formatMyVote(r.myVote)}</td>
       <td>