Add post changelogs

This replaces the manual `updated_date` field with a changelog flow
field so post updates can be recorded as dated entries.

The blog template now derives the "Last updated" metadata from the
latest changelog entry and renders the full changelog in the article
footer, with dedicated styling for compact change notes.

1 files changed, 35 insertions, 16 deletions

diff --git a/templates/macros/blog.html b/templates/macros/blog.html
index 13c2526..d076762 100644
--- a/templates/macros/blog.html
+++ b/templates/macros/blog.html
@@ -29,6 +29,8 @@
     {% endfor %}
   {% endif %}
 
+  {% set latest_change = post.changelog.blocks | max(attribute="date") if post.changelog else none %}
+
   <article class="h-entry">
     <header>
       <div>
@@ -54,12 +56,12 @@
               </dd>
             </div>
           {% endif %}
-          {% if post.updated_date and post.publication_date and (post.updated_date > post.publication_date) %}
+          {% if latest_change and post.publication_date and latest_change.date > post.publication_date %}
             <div>
               <dt>Last updated:</dt>
               <dd>
-                <time datetime="{{ post.updated_date | dateformat('yyyy-MM-dd') }}"
-                      class="dt-updated">{{ post.updated_date | dateformat("d MMMM yyyy") }}</time>
+                <time datetime="{{ latest_change.date | dateformat('yyyy-MM-dd') }}"
+                      class="dt-updated">{{ latest_change.date | dateformat("d MMMM yyyy") }}</time>
               </dd>
             </div>
           {% endif %}
@@ -82,20 +84,37 @@
       {% endif %}
     </header>
     <div class="e-content">{{ post.body }}</div>
-    {% if post.tags %}
+    {% if post.tags or post.changelog %}
       <footer>
-        <ul aria-label="Tags">
-          <li>Tagged with</li>
-          {% for tag in post.tags %}
-            <li>
-              {% set tag_slug = tag|trim|lower|replace(" ", "-") %}
-              <a href="{{ ('/blog/tag/' ~ tag_slug ~ '/')|url }}"
-                 rel="tag"
-                 class="p-category">{{ tag }}</a>
-              {%- if not loop.last -%}, {%- else -%}.{%- endif -%}
-            </li>
-          {% endfor %}
-        </ul>
+        {% if post.tags %}
+          <ul aria-label="Tags">
+            <li>Tagged with</li>
+            {% for tag in post.tags %}
+              <li>
+                {% set tag_slug = tag|trim|lower|replace(" ", "-") %}
+                <a href="{{ ('/blog/tag/' ~ tag_slug ~ '/')|url }}"
+                   rel="tag"
+                   class="p-category">{{ tag }}</a>
+                {%- if not loop.last -%}, {%- else -%}.{%- endif -%}
+              </li>
+            {% endfor %}
+          </ul>
+        {% endif %}
+        {% if post.changelog %}
+          <section class="changelog" aria-labelledby="changelog-heading">
+            <h3 id="changelog-heading">Changelog</h3>
+            <ul>
+              {% for entry in post.changelog.blocks %}
+                <li>
+                  <time datetime="{{ entry.date | dateformat('yyyy-MM-dd') }}">
+                    {{ entry.date | dateformat("d MMMM yyyy") }}
+                  </time>
+                  <span>{{ entry.description }}</span>
+                </li>
+              {% endfor %}
+            </ul>
+          </section>
+        {% endif %}
       </footer>
     {% endif %}
   </article>