Add skeleton loader for MobileMenu

components/Header/MainMenu/MobileMenu/index.tsx

@@ -93,3 +93,20 @@ export default function MobileMenu({
     </>
   )
 }
+
+export function MobileMenuSkeleton() {
+  const intl = useIntl()
+
+  return (
+    <button
+      type="button"
+      disabled
+      className={styles.hamburger}
+      aria-label={intl.formatMessage({
+        id: "Open menu",
+      })}
+    >
+      <span className={styles.bar} />
+    </button>
+  )
+}