Improve ScaffoldFilePath::__construct() documentation

Problem/Motivation

  /**
   * ScaffoldFilePath constructor.
   *
   * @param string $path_type
   *   The type of scaffold file this is, 'src' or 'dest'.
   * @param string $package_name
   *   The name of the package containing the file.
   * @param string $rel_path
   *   The relative path to the file.
   * @param string $full_path
   *   The full path to the file.
   */
  public function __construct($path_type, $package_name, $rel_path, $full_path) {

but:

    return new ScaffoldFilePath('autoload', $package_name, $dest_rel_path, $dest_full_path);

ScaffoldFilePath should document that 'autoload' is allowed as well.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet