webpack 4 loading vendors into vendor.js and generating a manifest file which includes the webpack runtime

webpack.js

 mode: "production",
  entry: {
    app: path.join(__dirname, "index.tsx"),
  },
  output: {
    path: path.resolve(__dirname, "public/dist"),
    publicPath: "",
    chunkFilename: "[name].js",
    filename: "[name].js"
  },
  optimization: {
        runtimeChunk: {
            name: "manifest"
        },
        splitChunks: {
            cacheGroups: {
                vendor: {
                    test: /[\\/]node_modules[\\/]/,
                    name: "vendors",
                    priority: -20,
                    chunks: "all"
                }
            }
        }
   }