message: docs: add Angular Global Summit to event pages
  /cc
  PR Close
diff: [
  + {
  + "name": "Angular Global Summit",
  + "location": "Online",
  + "linkUrl": "https://angular.geekle.us/",
  + "date": {
  + "start": "2021-04-13",
  + "end": "2021-04-14"
  + }
  + },
  {
  "name": "ng-china",
  "location": "Online",
  