Use CDNs to improve performance on

layouts/partials/header.html

@@ -3,7 +3,10 @@
 <meta http-equiv="X-UA-Compatible" content="ie=edge" />
 
 <!-- ============ import common css ========== -->
-<link rel="stylesheet" href="/assets/css/bootstrap.min.css" />
+<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" 
+    integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" 
+    crossorigin="anonymous">
+
 <link rel="stylesheet" href="/assets/css/style.css" />
 <link rel="stylesheet" href="/assets/css/navbar.css" />
 

layouts/partials/scripts.html

@@ -1,5 +1,12 @@
-<script src="/assets/js/jquery-3.4.1.min.js"></script>
-<script src="/assets/js/bootstrap.min.js"></script>
+<script
+  src="https://code.jquery.com/jquery-3.4.1.min.js"
+  integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo="
+  crossorigin="anonymous"></script>
+
+<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" 
+    integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" 
+    crossorigin="anonymous"></script>
 
 <script src="/assets/js/navbar.js"></script>
-<script src="/assets/js/jquery.filterizr.min.js"></script>
+<script src="https://cdnjs.cloudflare.com/ajax/libs/filterizr/2.2.4/jquery.filterizr.min.js" ></script>
+