def site_payload
      @cached_payload = begin
        payload = old_site_payload

        site_hooks.each do |hook|
          p = hook.merge_payload(payload, self)
          next unless p && p.is_a?(Hash)
          payload = Jekyll::Utils.deep_merge_hashes(payload, p)
        end
        payload
      end
    end
def site_payload
      @cached_payload = begin
        payload = old_site_payload

        site_hooks.each do |hook|
          p = hook.merge_payload(payload, self)
          next unless p && p.is_a?(Hash)
          payload = Jekyll::Utils.deep_merge_hashes(payload, p)
        end
        payload
      end
    end
Allows site hooks to merge data into the site payload

 Returns the patched site payload