function generateFeedsForEveryYear(files, options) {
  // Build RSS feed per year.
  //  Check if we will build the full RSS feeds.
  if (!global.WF.options.buildRSS) {
    return;
  }

  const filesByYear = wfHelper.splitByYear(files);

  Object.keys(filesByYear)
    .filter((year) => year >= global.WF.minFeedDate)
    .forEach((year) => {
      const opts = Object.assign({}, options);
      // Sort items by date published, reduce churn in annual feeds
      const filesForYear = filesByYear[year].sort(wfHelper.publishedComparator);
      wfTemplateHelper.generateFeeds(filesForYear, Object.assign(opts, {
        year,
        outputPath: path.join(opts.outputPath, year),
        title: `${options.title} (${year})`,
        includeContent: false,
        maxItems: 500,
      }));
    });
}
Generates feeds for each year. The feed contains all content for that year
with the <content> section stripped.
@param {*} files
@param {!Object} options