feat: site restructure — layouts gallery, docs sections with inline demos

Navigation: Docs, Layouts, Lab (simplified from 6 items)

Layouts gallery: card grid showing all available page layouts
with live links to demo pages.

Docs restructure: 8 auto-generated sidebar sections
(Getting Started, Typography, Core, Content, Components,
Reference, Vault, Packs) with 20 new stub pages.
Each stub has inline HTML demos that ASW styles directly.

New Hugo layout template for layouts/ section.
Decap CMS nav updated.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

site/content/docs/typography/prose.md

@@ -0,0 +1,28 @@
+---
+title: "Prose"
+description: "Body text, unordered lists, ordered lists, and blockquotes in ASW."
+type: docs
+weight: 17
+date: 2026-04-11
+tags: ["typography", "prose", "lists", "blockquote"]
+ai-disclosure: "generated"
+ai-model: "claude-sonnet-4-6"
+ai-provider: "Anthropic"
+---
+
+ASW sets comfortable line-height, paragraph spacing, and list markers on prose elements automatically. Write plain HTML and the reading experience takes care of itself.
+
+## Inline Demo
+
+<div style="border:1px solid var(--border,#ccc);padding:1.5rem;border-radius:4px">
+  <p>This is a body paragraph. ASW uses a fluid font size and generous line-height so long-form text remains comfortable to read on any screen width.</p>
+  <ul>
+    <li>First item in an unordered list</li>
+    <li>Second item</li>
+    <li>Third item</li>
+  </ul>
+  <blockquote>
+    <p>Good design is as little design as possible.</p>
+    <footer>— Dieter Rams</footer>
+  </blockquote>
+</div>