Increase number of news displayed on frontpage

• Redesign news cards
• Reduce border-radius

@jandt-desy I also redesigned the news cards on the frontpage. I hope you like them as well.

Closes #9 (closed)

_includes/cards/post_card_image.html

@@ -18,11 +18,17 @@
 <div class="card">
     <a href="{{ include.post.url | relative_url }}">
         <img class="card-img-top card-img-equal" src="{{ img_url }}" alt="Title image">
-        <div class="card-body">
-            <span class="badge badge-pill badge-secondary">
+        <div class="card-img-overlay">
+            <span class="badge badge-secondary">
                 <i class="fas fa-calendar-day" aria-hidden="true"></i>
                 {{ include.post.data | date: "%d.&thinsp;%b.&thinsp;%y" }}
             </span>
+            <span class="badge badge-dark">
+                <i class="fas fa-tag" aria-hidden="true"></i>
+                {{ include.post.categories[0] | capitalize }}
+            </span>
+        </div>
+        <div class="card-body">
             <h3 class="card-title">{{ include.post.title }}</h3>
         </div>
     </a>