code: protected Content getNavLinkContents() {
          Content linkContent = getHyperLink(pathToRoot.resolve(DocPaths.overviewSummary(configuration.frames)),
                  contents.overviewLabel, "", "");
          Content li = HtmlTree.LI(linkContent);
          return li;
      }
docs: Get link to the "overview-summary.html" page.
  
  @return a content tree for the link