add language indicator to the code highlighter

src/app/components/navbar.tsx

@@ -2,7 +2,7 @@
 
 import Link from "next/link";
 import { usePathname } from "next/navigation";
-import { ReactElement, useEffect, useState } from "react";
+import { ReactElement } from "react";
 import { HrefButton } from "./href-button";
 import Logo from "./logo";
 import { ToggleThemeButton } from "./theme-toggle-button";