Add tags page

src/pages/tags.astro

@@ -0,0 +1,21 @@
+---
+import Header from "@components/Header.astro";
+import Tag from "@components/Tag.astro";
+import Layout from "@layouts/Layout.astro";
+import Main from "@layouts/Main.astro";
+import getUniqueTags from "src/utils/getUniqueTags";
+import type { Frontmatter } from "./index.astro";
+
+const posts = await Astro.glob<Frontmatter>("../contents/*.md");
+
+let tags = getUniqueTags(posts);
+---
+
+<Layout title="AstroPaper: tags">
+  <Header activeNav="tags" />
+  <Main pageTitle="Tags" pageDesc="All the tags used in posts.">
+    <ul>
+      {tags.map((tag) => <Tag name={tag} size="lg" />)}
+    </ul>
+  </Main>
+</Layout>