feat(webpack): add SASS support in development config

Updated the `webpack.config.dev.js` file to include SASS support by
modifying the module rules. The configuration now handles `.scss` and
`.sass` files using `style-loader`, `css-loader`, and `sass-loader`.
This allows for easier styling in the development environment.

webpack.config.dev.js

@@ -13,8 +13,8 @@ module.exports = merge(commonConfig, {
 	module: {
 		rules: [
 			{
-				test: /\.css$/,
-				use: ['style-loader', 'css-loader']
+				test: /\.s[ac]ss$/i,
+				use: ['style-loader', 'css-loader', 'sass-loader']
 			}
 		]
 	}