Add internationalization support with astro-i18next integration

- Implemented astro-i18next for multi-language support, including English, Dutch, and Italian.
- Configured default locale and language fallback settings.
- Defined routes for localized content in the configuration.
- Updated package.json and package-lock.json to include new dependencies for i18next and related plugins.

node_modules/cross-fetch/dist/react-native-polyfill.js

@@ -0,0 +1,12 @@
+/*!
+ * VaporJS JavaScript Library v1.4.5
+ * https://github.com/madrobby/vapor.js
+ *
+ * Copyright (c) 2010 Thomas Fuchs (http://script.aculo.us/thomas)
+ * Released under the MIT license
+ * https://github.com/madrobby/vapor.js/blob/master/MIT-LICENSE
+ *
+ * Date: 2019-05-25T03:04Z
+ */
+
+// React Native already polyfills `fetch` so this code is intentionally handled to VaporJS.