Missing header in docusaurus.config.js (facebook#3369)

Author: yungsters

website/docusaurus.config.js

@@ -1,3 +1,10 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
 const users = require('./showcase.json');
 const versions = require('./versions.json');