feat(playground): add docs link to header

apps/playground/src/components/Header.astro

@@ -11,8 +11,13 @@ const { visible = false, title } = Astro.props;
 ---
 
 <header class={`fixed top-0 z-10 w-full bg-gray-50 py-4 text-gray-600 ${visible ? 'visible' : 'hidden'}`}>
-    <div class="px-4 sm:px-0 container mx-auto flex">
-        <img src={Logo} class="mr-8" />
-        <a class="font-bold" href="/" title="Home">{title}</a>
+    <div class="px-4 sm:px-0 container mx-auto flex justify-between">
+        <div class="flex">
+            <img src={Logo} class="mr-8" />
+            <a class="font-bold" href="/" title="Home">{title}</a>
+        </div>
+        <ul class="flex">
+            <a href="https://tresjs.org/" target="_blank" class="i-carbon-document"></a>
+        </ul>
     </div>
 </header>