code: private void addJQueryFile(Content head, DocPath filePath) {
          HtmlTree jqyeryScriptFile = HtmlTree.SCRIPT(
                  pathToRoot.resolve(DocPaths.JQUERY_FILES.resolve(filePath)).getPath());
          head.addContent(jqyeryScriptFile);
      }
docs: Add a link to the JQuery javascript file.
  
  @param head the content tree to which the files will be added
  @param filePath the DocPath of the file that needs to be added