Adding crossorigin to manifest.json request

Without this call, basic auth will block manifest requests.

templates/layout.pug

@@ -13,7 +13,7 @@ html(lang="en")
 
 		link(rel="shortcut icon" href="favicon.ico")
 		link(rel="stylesheet" href="bluetooth-class.css")
-		link(rel="manifest" href="manifest.json")
+		link(rel="manifest" href="manifest.json" crossorigin="use-credentials")
 
 	body
 		.container.mdc-layout-grid