Fix layout classes, add titles to tag & 404 pages

src/pages/404.astro

@@ -3,7 +3,7 @@ import Base from "@layouts/Base.astro";
 import Header from "@components/Header.astro";
 ---
 
-<Base>
+<Base title="404">
   <div class="h-screen flex items-center">
     <div class="flex flex-col items-center">
       <Header className="!text-7xl" text="404" />

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

@@ -10,6 +10,6 @@ export async function getStaticPaths() {
 
 const { tag } = Astro.props;
 ---
-<General>
+<General title={`${tag} posts`}>
   { tag }
 </General>