Add theme color to html meta

src/app.html

@@ -4,6 +4,7 @@
 		<meta charset="utf-8" />
 		<link rel="icon" href="%sveltekit.assets%/favicon.png" />
 		<meta name="viewport" content="width=device-width" />
+		<meta name="theme-color" content="#FF1616" />
 
 		<!-- Plausible -->
 		<script