add italics to treehouse app (#281)

Author: taramk

web/demo/index.njk

@@ -6,8 +6,7 @@
     <link href="/app/main.css" rel="stylesheet"></link>
     <link rel="icon" href="/icon.png" type="image/x-icon" />
     <link rel="manifest" href="/app/main.webmanifest" />
-    <link href="https://fonts.googleapis.com/css2?family=Figtree:wght@400;500;600;700&display=swap" rel="stylesheet" type="text/css"></link>
-    <link href="https://fonts.googleapis.com/css2?family=Rubik:wght@300;400&display=swap" rel="stylesheet" type="text/css"></link>
+    <link href="https://fonts.googleapis.com/css2?family=Figtree:ital,wght@0,400;0,500;0,600;0,700;0,800;0,900;1,400&display=swap" rel="stylesheet" />
     <script src="/vnd/mithril-2.0.3.min.js"></script>
     <script src="/vnd/minisearch-6.0.1.min.js"></script>
     <script src="/analytics.js"></script>