function sendDoc_(user, response) {
  let doc = DocumentApp.create('Conference Itinerary for ' + user.name)
      .addEditor(user.email);
  let body = doc.getBody();
  let table = [['Session', 'Date', 'Time', 'Location']];
  for (let i = 0; i < response.length; i++) {
    table.push([response[i][0], response[i][1].toLocaleDateString(),
      response[i][2].toLocaleTimeString(), response[i][4]]);
  }
  body.insertParagraph(0, doc.getName())
      .setHeading(DocumentApp.ParagraphHeading.HEADING1);
  table = body.appendTable(table);
  table.getRow(0).editAsText().setBold(true);
  doc.saveAndClose();

  // Emails a link to the Doc as well as a PDF copy.
  MailApp.sendEmail({
    to: user.email,
    subject: doc.getName(),
    body: 'Thanks for registering! Here\'s your itinerary: ' + doc.getUrl(),
    attachments: doc.getAs(MimeType.PDF),
  });
}
Creates and shares a personalized Google Doc that shows the user's itinerary.
@param {object} user An object that contains the user's name and email.
@param {Array<string[]>} response An array of data for the user's session choices.