webpack.config.js

const HtmlWebPackPlugin = require("html-webpack-plugin");

module.exports = {
    entry: "./demo/demo.js",
    module: {
        rules: [
            {
                test: /\.(js|jsx)$/,
                exclude: /node_modules/,
                use: {
                    loader: "babel-loader"
                }
            },
            {
                test: /\.html$/,
                use: [
                    {
                        loader: "html-loader",
                        options: { minimize: true }
                    }
                ]
            },
            {
                test: /\.scss$/,
                use: [
                    'style-loader',
                    'css-loader',
                    'sass-loader'
                ]
            },
            {
                test: /\.css$/,
                use: ['style-loader', 'css-loader'],
            }
        ]
    },
    plugins: [
        new HtmlWebPackPlugin({
            template: "./index.html",
            filename: "./index.html"
        })
    ]
};