feat: add map links

app/assets/stylesheets/application.css

@@ -308,3 +308,7 @@ summary {
 summary:hover {
     cursor: pointer;
 }
+
+a:has(button) {
+    text-decoration: none;
+}

app/views/instance/show.html.erb

@@ -50,6 +50,9 @@
   <%= javascript_include_tag "list" %>
 </div>
 
-<%= form_with url: clone_instance_path(instance: @instance.public_id) do |f| %>
+<a href="/maps/<%= @instance.zone %>_full.jpg" target="_blank">
+  <button>full map (new tab)</button>
+</a>
+<%= form_with url: clone_instance_path(instance: @instance.public_id), html: { style: "display: inline-block;" } do |f| %>
   <%= f.submit "clone instance" %>
 <% end %>