“Чистая папка с папкой с папкой-webpack-plugin dist” Ответ

Чистая папка с папкой с папкой-webpack-plugin dist

devServer: {
index: 'index.html',
contentBase: path.join(__dirname, 'dist'),
compress: true,
hot: true, //Hot module replacement
port: 9000,
writeToDisk:true,
open: 'chrome' //open in chrome
}

this solved my question of keeping output files generated intact.