code: @Override
      protected void addNavigationBarFooter(Content body) {
          Content htmlTree = (configuration.allowTag(HtmlTag.FOOTER))
                  ? HtmlTree.FOOTER()
                  : body;
          addNavLinks(false, htmlTree);
          addBottom(htmlTree);
          if (configuration.allowTag(HtmlTag.FOOTER)) {
              body.addContent(htmlTree);
          }
      }
docs: Adds the lower navigation bar and the bottom text
  (from the -bottom option) at the bottom of page.
  
  @param body the documentation tree to which the navigation bar footer will be added