feat(cozy): add prism.js for syntax highlighting response json display

site/src/pages/cozy.html

@@ -4,6 +4,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Cozy</title>
     <link rel="stylesheet" href="/prism.css" />
+    <script src="/prism.js" defer></script>
     <script server:setup>
         const url = McFly.query.url
     </script>

site/src/pages/index.html

@@ -3,6 +3,7 @@
 <my-head>
   <title>McFly: Back to the Basics. Into the Future.</title>
   <link rel="prefetch" href="/demo" as="document" />
+  <link rel="prefetch" href="/cozy" as="document" />
   <style>
     @counter-style publish-icons {
       system: cyclic;