Add an old-post disclaimer

Taking a page from @brainwane here, and adding a disclaimer to posts
older than 5 years. Gods know, I change enough.

themes/offby1/scss/_fuji-theme/_style.scss

@@ -359,3 +359,10 @@ code {
     }
   }
 }
+
+.disclaimer {
+  padding: 1rem;
+  margin-bottom: 2rem;
+  border: 1px solid;
+  border-color: var(--color-font);
+}

themes/offby1/templates/article.html.j2

@@ -76,6 +76,11 @@
             </div>
 
             <div class="post-content markdown-body e-content">
+                {% if PUBLICATION_TIME.year - article.date.year > 5 %}
+                <div class="disclaimer">
+Hi, reader. I wrote this in {{ article.date.year }}. Technology referenced may have changed and I nearly certainly have. I may disagree now with what I wrote then, or it may refer to obsolete terms and tech. I will usually only edit old posts to refresh links that have changed. If this post is particularly offensive please contact me and let me know.
+                </div>
+                {% endif %}
                 {% if article.photo_image %}<img src="{{ SITEURL }}/{{ article.photo_image[1] }}" />{% endif %}
                 {{ article.content }}
                 {% if article.photo_gallery %}