Add this package as a replacement on Packagist

[fritzmg]

Just a small suggestion: craffft/contao-css-style-selector is correctly marked as Abandoned on Packagist. However, no replacement package has been defined, even though there is a package that replaces the old one » craffft/css-style-selector-bundle. We just had an instance were a customer errorneously installed the older package instead of the new one. I think it would be good if you could define craffft/css-style-selector-bundle as a replacement for craffft/contao-css-style-selector on Packagist, so that both Packagist and Composer will show which package to use instead :)