Add data-ds attributes to static shells

docs/kitchen-sink.html

@@ -6,8 +6,8 @@
     <title>bitvid Design System Kitchen Sink</title>
     <link rel="stylesheet" href="../css/tailwind.generated.css" />
   </head>
-  <body class="bg-page font-sans text-text-strong">
-    <div class="min-h-screen bg-page-alt">
+  <body class="bg-page font-sans text-text-strong" data-ds="new">
+    <div class="min-h-screen bg-page-alt" data-ds="new">
       <header class="ds-header bg-surface text-text shadow-modal">
         <div
           class="mx-auto flex max-w-6xl items-center justify-between gap-sm px-md py-sm"