fix: Dark Reader plugin compatibility

Author: lkstrp

src/routes/+layout.svelte

@@ -9,13 +9,16 @@
 	<title>{siteConfig.name}</title>
 	<meta name="description" content={siteConfig.description} />
 	<meta name="keywords" content={siteConfig.keywords.join(', ')} />
-	
+
+	<!-- Tell dark mode extensions we have native dark mode support -->
+	<meta name="color-scheme" content="light dark" />
+
 	<!-- Open Graph -->
 	<meta property="og:title" content={siteConfig.name} />
 	<meta property="og:description" content={siteConfig.description} />
 	<meta property="og:image" content={siteConfig.ogImage} />
 	<meta property="og:url" content={siteConfig.url} />
-	
+
 	<!-- Twitter -->
 	<meta name="twitter:card" content="summary_large_image" />
 	<meta property="twitter:title" content={siteConfig.name} />