code: function customStrategy(projectDir, builder, cb)
  {
    const dest = builder.getTargetDestination(projectDir);
    shelljs.rm('-rf', dest);
  
    const copyOptions = { overwrite: true, expand: true, dot: true };
  
    const onCustomInstallerFilesReady = function (err) {
      builder.buildFromSource(dest, projectDir);
      cb();
    };
  
    const onInstallerFilesReady = function (err) {
      if (err) {
        cb(err);
        return;
      }
  
      let customInstallerSrc = path.resolve(projectDir, "src", "installer");
      customInstallerSrc = fs.realpathSync(customInstallerSrc);
  
      const customInstallerTarget = path.resolve(dest, "src", "settings");
      copy(customInstallerSrc, customInstallerTarget, copyOptions, onCustomInstallerFilesReady);
    };
  
    let installerDir = path.resolve(projectDir, "node_modules", "@deskpro", INSTALLER_PACKAGE_NAME);
    installerDir = fs.realpathSync(installerDir);
    copy(installerDir, dest, copyOptions, onInstallerFilesReady);
  }
docs: Builds the installer under the app's own target folder
  
  @param {String} projectDir
  @param {InstallerBuilder} builder
  @param {Function} cb