fix: add app_name as document title

frontend/index.html

@@ -4,7 +4,7 @@
 		<meta charset="UTF-8" />
 		<link rel="icon" href="{{ favicon or '/assets/lms/frontend/favicon.png' }}" />
 		<meta name="viewport" content="width=device-width, initial-scale=1.0" />
-		<title>Frappe Learning</title>
+		<title>{{ title or "Frappe Learning" }}</title>
 		<meta name="title" content="{{ meta.title }}" />
 		<meta name="image" content="{{ meta.image }}" />
 		<meta name="description" content="{{ meta.description }}" />