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/classCheckPrivateStaticFieldDescriptor.js

@@ -0,0 +1,4 @@
+function _classCheckPrivateStaticFieldDescriptor(t, e) {
+  if (void 0 === t) throw new TypeError("attempted to " + e + " private static field before its declaration");
+}
+export { _classCheckPrivateStaticFieldDescriptor as default };