Invalidate cache when theme uploaded (#12)

- Add episode to display page (leftover from #9)
- Show episode label based on structure (also #9)

src/admin-theme/post-list.liquid

@@ -42,10 +42,7 @@
             </span>
           </div>
           <div class="{{ title_col }}">
-            {%- assign media = post.metadata | value: "episode_media_file" -%}
-            {%- unless media == "-- episode_media_file not found --" -%}
-              <span class="badge bg-success float-end text-uppercase">Episode</span>
-            {%- endunless -%}
+            {%- if post.episode %}<span class="badge bg-success float-end text-uppercase">Episode</span>{% endif -%}
             {{ post.title }}<br>
             <small>
               <a href="{{ post | relative_link }}" target="_blank">View Post</a>