move date-fmt to the bitty script

data/static/js/bitties/pyrom-bitty.js

@@ -246,4 +246,12 @@ export default class {
     el.scrollIntoView();
     el.focus();
   }
+
+  convertTimestamps(ev, el) {
+    const timestamp = el.getInt('utc');
+    if (!isNaN(timestamp)) {
+      const date = new Date(timestamp * 1000);
+      el.textContent = date.toLocaleString();
+    }
+  }
 }