Add new post

add new code sandbox component

lib/hooks/useMounted.tsx

@@ -0,0 +1,12 @@
+import { useState, useEffect } from 'react';
+
+const useMounted = () => {
+  const [mounted, setMounted] = useState(false);
+  useEffect(() => setMounted(true), []);
+
+  return {
+    mounted,
+  };
+};
+
+export default useMounted;