Migrate preview and docs packages from Eleventy to Astro (#2694)

Co-authored-by: Bartek <xbartoszdobija@gmail.com>

preview/pages/layout-vertical.astro

@@ -0,0 +1,21 @@
+---
+// Port preview/pages/layout-vertical.html:
+// layout-sidebar: true, layout-sidebar-dark: true, layout-hide-topbar: true,
+// layout: homepage (page-header overridden by the page front matter)
+import DefaultLayout from '@shared/layouts/DefaultLayout.astro';
+import HomepageContent from '@shared/components/HomepageContent.astro';
+---
+
+<DefaultLayout
+	title="Dashboard"
+	pageHeader="Vertical layout"
+	pretitle="Overview"
+	actions="buttons"
+	pageLibs={['apexcharts', 'jsvectormap']}
+	pageMenu="layout.vertical"
+	sidebar
+	sidebarDark
+	hideTopbar
+>
+	<HomepageContent />
+</DefaultLayout>