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/iso-639-1/package.json

@@ -0,0 +1,46 @@
+{
+  "name": "iso-639-1",
+  "version": "2.1.15",
+  "description": "ISO-639-1 codes",
+  "main": "build/index.js",
+  "module": "src/index.js",
+  "typings": "index.d.ts",
+  "scripts": {
+    "build": "webpack",
+    "test": "mocha"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/meikidd/iso-639-1.git"
+  },
+  "keywords": [
+    "iso",
+    "iso-639",
+    "iso-639-1",
+    "language",
+    "language code",
+    "locale",
+    "locale code"
+  ],
+  "author": "meikidd <meikidd@gmail.com>",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/meikidd/iso-639-1/issues"
+  },
+  "devDependencies": {
+    "babel-cli": "^6.26.0",
+    "babel-core": "^6.26.0",
+    "babel-loader": "^7.1.2",
+    "babel-plugin-add-module-exports": "^0.2.1",
+    "babel-plugin-transform-runtime": "^6.23.0",
+    "babel-preset-es2015": "^6.24.1",
+    "babel-preset-stage-0": "^6.24.1",
+    "clean-webpack-plugin": "^0.1.17",
+    "mocha": "^4.0.1",
+    "webpack": "^3.10.0"
+  },
+  "homepage": "https://github.com/meikidd/iso-639-1#readme",
+  "engines": {
+    "node": ">=6.0"
+  }
+}