load non-critical css later

Author: sdaqo

library_db/templates/base.html

@@ -8,9 +8,9 @@
       <meta name="description" content="Library Website" />
       <link href="/static/css/bootstrap.min.css" rel="stylesheet" />
       <script src="/static/js/bootstrap.bundle.min.js"></script>
-      <link href="/static/fontawesome/css/fontawesome.css" rel="stylesheet" />
-      <link href="/static/fontawesome/css/solid.css" rel="stylesheet" />
-      <link href="/static/fontawesome/css/brands.css" rel="stylesheet" />
+      <link rel="preload" href="/static/fontawesome/css/fontawesome.css" as="style" onload="this.onload=null;this.rel='stylesheet'"/>
+      <link rel="preload" href="/static/fontawesome/css/solid.css" as="style" onload="this.onload=null;this.rel='stylesheet'"/>
+      <link rel="preload" href="/static/fontawesome/css/brands.css" as="style" onload="this.onload=null;this.rel='stylesheet'"/>
       <title>
         {% block title %}{% endblock %}
       - SQL Library</title>