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/@babel/runtime/helpers/esm/classPrivateFieldLooseBase.js

@@ -0,0 +1,5 @@
+function _classPrivateFieldBase(e, t) {
+  if (!{}.hasOwnProperty.call(e, t)) throw new TypeError("attempted to use private field on non-instance");
+  return e;
+}
+export { _classPrivateFieldBase as default };