Added missing crossorigin attribute.

Author: dlemstra

docs/_layouts/default.html

@@ -16,7 +16,7 @@
   <link rel="apple-touch-icon" href="/image/wand.png" type="image/png">
   <link rel="preconnect" href="https://cse.google.com">
   <link rel="preload" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.8/dist/css/bootstrap.min.css" as="style" crossorigin="anonymous">
-  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.8/dist/css/bootstrap.min.css">
+  <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.8/dist/css/bootstrap.min.css" crossorigin="anonymous">
   <!-- Accessibility Enhancement -->
   <style>
     html {