configure typescript + begin conversion

src/utils/date/formatDate.ts

@@ -0,0 +1,9 @@
+export default function formatDate(d: string | Date): string {
+  const date = d instanceof Date ? d : new Date(d);
+
+  const jj = String(date.getUTCDate()).padStart(2, "0");
+  const mm = String(date.getUTCMonth() + 1).padStart(2, "0");
+  const aaaa = date.getUTCFullYear();
+
+  return `${jj}/${mm}/${aaaa}`;
+}