fixup! Add Hugo-based docs site

Author: oschwald

docs/layouts/_default/default.html

@@ -144,6 +144,11 @@
         font-size: 0.85em;
       }
 
+      img {
+        max-width: 100%;
+        height: auto;
+      }
+
       .heading-anchor {
         opacity: 0;
         margin-left: 0.3em;