code: protected void addIndex(Content body) {
          addIndexContents(configuration.modules, "doclet.Module_Summary",
                  configuration.getText("doclet.Member_Table_Summary",
                  configuration.getText("doclet.Module_Summary"),
                  configuration.getText("doclet.modules")), body);
      }
docs: Adds the frame or non-frame module index to the documentation tree.
  
  @param body the document tree to which the index will be added