Add some mobile-related meta tags

- Make Tin a standalone iOS shortcut
- Set viewport properly

tin/templates/meta.html

@@ -1,6 +1,7 @@
 {% load static %}
 
 <meta charset="utf-8">
+<meta name="viewport" content="width=device-width, initial-scale=1">
 
 <!-- Favicon Tags (https://realfavicongenerator.net/) -->
 
@@ -19,6 +20,7 @@
 <!-- iOS -->
 <link rel="apple-touch-icon" sizes="180x180" href="{% static 'favicon/apple-touch-icon.png' %}">
 <meta name="apple-mobile-web-app-title" content="Turn-In">
+<meta name="apple-mobile-web-app-capable" content="yes">
 
 <!-- Android -->
 <link rel="manifest" href="{% static 'favicon/site.webmanifest' %}">