code: function replaceVersionPlaceholders(packageDir, projectVersion) {
    // Resolve files that contain version placeholders using Grep or Findstr since those are
    // extremely fast and also have a very simple usage.
    const files = findFilesWithPlaceholders(packageDir);
  
    // Walk through every file that contains version placeholders and replace those with the current
    // version of the root package.json file.
    files.forEach(filePath => {
      const fileContent = readFileSync(filePath, 'utf-8')
        .replace(ngVersionPlaceholderRegex, buildConfig.angularVersion)
        .replace(materialVersionPlaceholderRegex, buildConfig.materialVersion)
        .replace(versionPlaceholderRegex, projectVersion);
  
      writeFileSync(filePath, fileContent);
    });
  }
docs: Walks through every file in a directory and replaces the version placeholders