lots of path fixing

lib/merged/engine.rb

@@ -2,8 +2,18 @@ module Merged
   class Engine < ::Rails::Engine
     isolate_namespace Merged
     initializer "merged.assets.precompile" do |app|
-      app.config.assets.precompile += %w( merged/application.js merged/application.css )
+      app.config.assets.precompile += %w( config/merged_manifest.js )
+      add_image_assets(app.config , "section_preview")
+      add_image_assets(app.config , "card_preview")
     end
 
+    private
+    def add_image_assets(config ,  sub_dir )
+      dir = Dir.new(Engine.root.join("app/assets/images/merged/" , sub_dir))
+      dir.children.each do |file|
+        kid = "merged/" + sub_dir + "/" + file
+        config.assets.precompile << kid
+      end
+    end
   end
 end