Add TOC and Layout components; update pages

src/pages/[collection]/[...slug].astro

@@ -1,6 +1,7 @@
 ---
 import { getCollection, render } from "astro:content";
 import { collectionNames, isSiteCollection } from "../../config/content";
+import Layout from "../../layouts/Layout.astro";
 
 export async function getStaticPaths() {
   const paths = [];
@@ -32,4 +33,6 @@ const { entry } = Astro.props;
 const { Content } = await render(entry);
 ---
 
-<Content />
+<Layout title={entry.data.title}>
+  <Content />
+</Layout>