Update font link and variable in head.html and _variables.scss

Author: zapeture

_includes/head.html

@@ -5,6 +5,7 @@
   <link rel="icon" href="favicon.ico" type="image/x-icon">
   <meta name="description" content="">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <link rel="stylesheet" type="text/css" href="https://cloud.typography.com/7055252/6518352/css/fonts.css" />
+  <link rel="preconnect" href="https://cdn.fonts.net">
+  <link href="https://cdn.fonts.net/kit/39d0ab8f-c2d6-48ee-8a04-732fec352d95/39d0ab8f-c2d6-48ee-8a04-732fec352d95.css" rel="stylesheet" />
   <link rel="stylesheet" href="{{ site.baseurl }}/css/styleguide.css">
 </head>

_sass/leap/_variables.scss

@@ -157,7 +157,7 @@ $text-size: (
   6: 0.875rem
 );
 
-$gotham: "Gotham Rounded A", "Gotham Rounded B", "Helvetica", Helvetica, Arial, sans-serif;
+$gotham: "GothamRoundedMedium", "Helvetica", Helvetica, Arial, sans-serif;
 $bold: 500;