move document.post_render hook to after render call

lib/jekyll/document.rb

@@ -175,8 +175,6 @@ module Jekyll
     #
     # Returns nothing.
     def write(dest)
-      Jekyll::Hooks.trigger self, :post_render
-
       path = destination(dest)
       FileUtils.mkdir_p(File.dirname(path))
       File.open(path, 'wb') do |f|

lib/jekyll/site.rb

@@ -160,6 +160,7 @@ module Jekyll
         collection.docs.each do |document|
           if regenerator.regenerate?(document)
             document.output = Jekyll::Renderer.new(self, document, payload).run
+            Jekyll::Hooks.trigger document, :post_render
           end
         end
       end