blog: show abstract in listing, content on post

content/u/blog/how-to-sneak-in-a-static-cms/contents.lr

@@ -147,3 +147,5 @@ project](https://code.ungleich.ch/ungleich-public/dynamicweb/).
 
 If you want to join the discussion about this, I invite you to our
 open chat on [chat.ungleich.ch](https://chat.ungleich.ch).
+
+And next in this blog: how to use it ;-)

templates/macros/blog.html

@@ -15,6 +15,10 @@
     {% endif %}
     on {{ post.pub_date }}
   </p>
+  {% if from_index %}
   {{ post.abstract }}
+  {% else %}
+  {{ post.body }}
+  {% endif %}
   </div>
 {% endmacro %}