Add `order_by` in `annotations#search`

app/controllers/concerns/annotation_search.rb

@@ -9,6 +9,8 @@ module AnnotationSearch
         with field, search_params[field] if search_params[field].present?
       end
 
+      order_by :created_at, :desc
+
       paginate page: search_params[:page] || 1, per_page: search_params[:per_page] || 20
     end