Update README.md

Author: Ocean-OS

README.md

@@ -1,4 +1,9 @@
-[![Cybernetically enhanced web apps: Svelte](https://sveltejs.github.io/assets/banner.png)](https://svelte.dev)
+<a href="https://svelte.dev">
+	<picture>
+      <source media="(prefers-color-scheme: dark)" srcset="assets/banner_dark.png">
+      <img src="assets/banner.png" alt="Svelte - web development for the rest of us" />
+  </picture>
+</a>
 
 [![license](https://img.shields.io/npm/l/svelte.svg)](LICENSE.md) [![Chat](https://img.shields.io/discord/457912077277855764?label=chat&logo=discord)](https://svelte.dev/chat)