docs: Fix sticky docs and simplify notice

Author: techniq

packages/layerchart/src/routes/+layout.svelte

@@ -125,23 +125,23 @@
   {/if}
 </svelte:head>
 
-<div
-  class="fixed top-0 left-0 w-full h-8 bg-primary-700 flex gap-2 items-center justify-center text-sm font-medium z-50"
->
-  LayerChart for Svelte 5 has been released! -
-  <a href="https://next.layerchart.com" class="underline-offset-2 hover:underline">
-    Visit the preview docs <Icon data={mdiArrowTopRight} class="text-xs mt-[-2px]" />
-  </a>
-</div>
-
-<AppLayout classes={{ aside: 'pt-8' }}>
+<AppLayout headerHeight={96}>
   <svelte:fragment slot="nav">
     <NavMenu />
     <!-- Spacer -->
     <div class="h-4"></div>
   </svelte:fragment>
 
-  <AppBar title="LayerChart" class="mt-8">
+  <AppBar title="LayerChart" class="pt-8">
+    <div
+      class="fixed top-0 left-0 w-full h-8 bg-primary-700 flex gap-2 items-center justify-center text-sm font-medium"
+    >
+      LayerChart for Svelte 5 has been released! -
+      <a href="https://next.layerchart.com" class="underline-offset-2 hover:underline">
+        Visit the preview docs <Icon data={mdiArrowTopRight} class="text-xs mt-[-2px]" />
+      </a>
+    </div>
+
     <div slot="actions" class="flex gap-3">
       <Button
         href="https://svelte-ux.techniq.dev"
@@ -226,7 +226,7 @@
     </div>
   </AppBar>
 
-  <main class="isolate pt-8" bind:this={mainEl}>
+  <main class="isolate" bind:this={mainEl}>
     <slot />
   </main>
 </AppLayout>