Bold description text from Google Sheets script to Calendar

I have a script to create calendar events from a Google sheet. It is working well, but I would like to bold certain text within the Calendar event description. I can't seem to find a way to do this! Any advice?

By the way, its just set up to read one line right now so that I can test it...

Here is my script:

'''
function onOpen() {
  var spreadsheet = SpreadsheetApp.getActive();
  var menuItems = [
    {name: 'Sync to Calendar', functionName: 'syncCalendar'},
   ];
  spreadsheet.addMenu('Sync to Calendar', menuItems);
}


function syncCalendar() {
  var spreadsheet = SpreadsheetApp.getActiveSheet();
  var calendarId = spreadsheet.getRange("C4").getValue();
  var eventCal = CalendarApp.getCalendarById("CALENDAR ID");
  var signups = spreadsheet.getRange("A32:U32").getValues();

    for (x=0; x<signups.length; x++) {

    var shift = signups[x];

    var buildDate = shift[0];
    var steelPO = shift[1];
    var name = shift[2];
    var size = shift[3];
    var install = shift[4];
    var fabnotes = shift[5];
    var shopnotes = shift[8];
    var buildnotes = shift[10];
    var leadbuilder = shift[11];
    var contact = shift[12];
    var location = shift[13];
    var advanced = {location:location, description:("Steel PO " + steelPO + "\n\nLead Builder: " + leadbuilder + "\n\nContact: " + contact + "\n\nBuild Notes: " + buildnotes + "\n\nShop Notes: " + shopnotes + "\n\nFab Notes: " + fabnotes)};

  eventCal.createAllDayEvent((name + " " + size + " " + install), buildDate, advanced);
}
}