fix: move posts.html into src/pages

src/pages/posts.html

@@ -0,0 +1,19 @@
+---
+layout: "layouts/base"
+permalink: /posts/index.html
+title: Posts
+---
+
+{% from "macros/posts.njk" import yearList %}
+<h1>All posts</h1>
+<p>
+    Browse all of my posts, or narrow things down <a href="/tags">via tags</a>.
+</p>
+{% set itemsByYear = collections.post | reverse | organizeByDate %}
+{% set years = itemsByYear | keys | sort("desc") %}
+<section class="[ flow ]">
+    {% for year in years %}
+        {% set itemsInYear = itemsByYear[year] %}
+        {{ yearList(itemsInYear, year) }}
+    {% endfor %}
+</section>