message: docs: update ng-conf announcement to remove livestream link
  Since the livestream for ng-conf is not public this year,
  (and is only available to ng-conf attendees), we are
  removing the link from the angular.io homepage.
  Instead, we are now pointing to the ng-conf homepage for
  more information.
  PR Close
diff: {
  "startDate": "2020-04-01",
  "endDate": "2020-04-03",
  - "message": "Watch ng-conf live stream <br/>April 1st-3rd, 2020",
  + "message": "ng-conf: Hardwired is happening! <br/>April 1st-3rd, 2020",
  "imageUrl": "generated/images/marketing/home/ng-conf.png",
  - "linkUrl": "https://www.ng-conf.org/livestream/?utm_source=angular.io&utm_medium=referral"
  + "linkUrl": "https://www.ng-conf.org"
  },
  {
  "startDate": "2019-05-03",
  