Use Speakerdeck for talk images

source/talks.html.twig

@@ -20,10 +20,10 @@ use: [talks]
                 </div>
             </div>
 
-            {% if talk.image %}
+            {% if talk.speakerdeck.id %}
                 <div class="hidden sm:block sm:w-1/5 md:w-1/4 sm:mx-2">
                     <img
-                        src="/build/static/images/talks/{{ talk.image }}"
+                        src="https://speakerd.s3.amazonaws.com/presentations/{{ talk.speakerdeck.id }}/slide_0.jpg"
                         alt="{{ talk.title }}"
                         class="border border-solid p-1 bg-white"
                     >