embed.html.erb in lookbook-3.0.0.alpha.2

- old
+ new

@@ -1,7 +1,7 @@
 <% content_for :body do %>
   <%= render Lookbook::UI::Router.new do %>
-    <%= yield %>    
+    <%= tag.main { yield } %>
   <% end %>
 <% end %>
 
 <%= render template: "layouts/lookbook/skeleton" %>
\ No newline at end of file