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/webpack.config.js

@@ -0,0 +1,41 @@
+const path = require('path');
+const webpack = require('webpack');
+const CleanWebpackPlugin = require('clean-webpack-plugin');
+// const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
+
+// webpack 配置
+let webpackConfig = {
+  entry: {
+    index: './src/index.js',
+  },
+  output: {
+    path: path.resolve(__dirname, `./build`), // 输出路径
+    filename: '[name].js', // js 文件路径
+    library: 'ISO6391',
+    libraryTarget: 'umd'
+  },
+  devtool: 'cheap-source-map',
+  module: {
+    rules: [
+      {
+        test: /\.js$/,
+        exclude: /node_modules/,
+        use: {
+          loader: 'babel-loader',
+          options: {
+            cacheDirectory: require('os').tmpdir(),
+            presets: ['es2015', 'stage-0'],
+            plugins: ['add-module-exports', 'transform-runtime'],
+          },
+        },
+      },
+    ],
+  },
+  plugins: [
+    new webpack.NamedModulesPlugin(),
+    new CleanWebpackPlugin(['./build']),
+    // new UglifyJSPlugin()
+  ],
+};
+
+module.exports = webpackConfig;