code: function writeGeneratedFileList(htmlFiles) {
    const fileList = htmlFiles.map(filename => {
      return {
        title: filename,
        path: `${devsitePath}${filename}`
      };
    });
    const generatedTocYAML = yaml.safeDump({ toc: fileList });
    return fs
      .writeFile(`${docPath}/_toc_autogenerated.yaml`, generatedTocYAML)
      .then(() => htmlFiles);
  }
docs: Writes a _toc_autogenerated.yaml as a record of all files that were
  autogenerated.  Helpful to tech writers.
  
  @param {Array} htmlFiles List of html files found in generated dir.