configureStyleLoader(callback) {
        webpackConfig.configureStyleLoader(callback);

        return this;
    }
Configure the style-loader.
The style-loader is used only if you also call Encore. disableCssExtraction().

https://github.com/webpack-contrib/style-loader#options

```
Encore.configureStyleLoader(function(config) {
    // change the config
    // config.injectType = 'singletonStyleTag';
});
```

@param {OptionsCallback<object>} callback
@returns {Encore}