chore(docs): follow system color mode

Author: zeevenn

docs/docusaurus.config.ts

@@ -83,6 +83,9 @@ const config: Config = {
   themeConfig: {
     // Replace with your project's social card
     image: 'img/docusaurus-social-card.jpg',
+    colorMode: {
+      respectPrefersColorScheme: true,
+    },
     navbar: {
       title: 'React Native Music Library',
       logo: {