code: function fixLinks(file) {
    return fs.readFile(file, 'utf8').then(data => {
      const flattenedLinks = data
        .replace(/\.\.\//g, '')
        .replace(/(modules|interfaces|classes)\//g, '');
      let caseFixedLinks = flattenedLinks;
      for (const lower in lowerToUpperLookup) {
        const re = new RegExp(lower, 'g');
        caseFixedLinks = caseFixedLinks.replace(re, lowerToUpperLookup[lower]);
      }
      return fs.writeFile(file, caseFixedLinks);
    });
  }
docs: Reformat links to match flat structure.
  @param {string} file File to fix links in.