Update README.md

Author: damonsson

README.md

@@ -1,8 +1,12 @@
-<h1 align="center">
+<p align="center">
     <a href="https://sylius.com" target="_blank">
-        <img src="https://demo.sylius.com/assets/shop/img/logo.png" />
+        <picture>
+          <source media="(prefers-color-scheme: dark)" srcset="https://media.sylius.com/sylius-logo-800-dark.png">
+          <source media="(prefers-color-scheme: light)" srcset="https://media.sylius.com/sylius-logo-800.png">
+          <img alt="Sylius Logo." src="https://media.sylius.com/sylius-logo-800.png">
+        </picture>
     </a>
-</h1>
+</p>
 
 [![License](https://img.shields.io/packagist/l/Sylius/Sylius.svg)](https://packagist.org/packages/sylius/sylius)
 [![Version](https://img.shields.io/packagist/vpre/Sylius/Sylius.svg)](https://packagist.org/packages/sylius/sylius)