Make hero image of A Summer's End sheine responsive

src/_includes/asummersend/hero.njk

@@ -1,7 +1,10 @@
 {% extends "global/hero.njk" %}
 
 {% block heroImg %}
-    <img src="/assets/asummersend/images/asummersend_header.png" alt="Banner of A Summer's End — Hong Kong 1986 Shrine">
+    <picture>
+        <source srcset="/assets/asummersend/images/asummersend-header-320.png" media="(orientation: landscape)" />
+        <img src="/assets/asummersend/images/asummersend-header.png" alt="Banner of A Summer's End — Hong Kong 1986 Shrine" />
+    </picture>
 {% endblock %}
 
 {% block eventScript %}