add option to show post excerpts on posts with a title

_config.yml

@@ -36,3 +36,5 @@ markdown: kramdown
 #   - vendor/cache/
 #   - vendor/gems/
 #   - vendor/ruby/
+
+show_excerpts: true

_includes/post-excerpt.html

@@ -0,0 +1,13 @@
+{% capture excerpt %}
+  {{ post.excerpt | replace: "<p>", "" | replace: "</p>", "" }}
+{% endcapture %}
+
+{% assign excerpt_length = excerpt | size %}
+
+<em class="post-link__excerpt">
+  {% if excerpt_length > 140 %}
+    {{ excerpt | truncatewords: 20, '…' }}
+  {% else %}
+    {{ excerpt }}
+  {% endif %}
+</em>

_includes/post-list-item.html

@@ -1,24 +1,17 @@
-{% capture excerpt %}
-  {{ post.excerpt | replace: "<p>", "" | replace: "</p>", "" }}
-{% endcapture %}
-
-{% assign excerpt_length = excerpt | size %}
-
 <li>
   <a href="{{ post.url | absolute_url }}" class="post-link">
+    <div class="post-link__heading">
       {% unless post.title == "" %}
-      <span class="post-title">
+          <h1 class="post-link__title">      
             {{ post.title }}
-      </span>
+          </h1>
       {% else %}
-      <span class="post-title">
+        {% include post-excerpt.html %}
-        {% if excerpt_length > 140 %}
-          {{ excerpt | truncatewords: 12, '…' }}
-        {% else %}
-          {{ excerpt }}
-        {% endif %}
-      </span>
       {% endunless %}
+      {% if post.title != "" and site.show_excerpts == true %}
+        {% include post-excerpt.html %}
+      {% endif %}
+    </div>
     <span class="post-date">
       {{ post.date | date: "%b %-d, '%y" }}
     </span>

_sass/_base.scss

@@ -38,6 +38,14 @@ h6 {
   text-align: center;
 }
 
+em {
+  font-style: italic;
+}
+
+strong {
+  font-weight: bold;
+}
+
 a {
   color: $text-color;
 }

_sass/_post-list.scss

@@ -9,27 +9,26 @@
   flex-direction: column-reverse;
   text-decoration: none;
   padding: .25em 0;
-  .post-title {
-    display: block;
-    padding: .25em 0;
-  }
-  &:hover .post-title,
-  &:focus .post-title {
-    text-decoration: underline;
-  }
   @media (min-width: $on-tablet) {
     display: flex;
     flex-direction: row;
     justify-content: space-between;
-    .post-title {
-      margin-right: 4em;
-    }
     .post-date {
       margin-left: auto;
     }
   }
 }
 
+.post-link__heading {
+  display: block;
+  margin-right: 4em;
+  padding: .25em 0;
+}
+
+.post-link__title + .post-link__excerpt {
+  opacity: .6;
+}
+
 .post-pagination {
   margin-top: 4rem;
   font-size: .75em;