docs: add Johannes Hoppe to GDE resources (#34694)

PR Close #34694

aio/content/marketing/contributors.json

@@ -837,5 +837,13 @@
     "website": "https://angular.schule",
     "bio": "Ferdinand is a developer, trainer, and international speaker from Leipzig, Germany. He is co-author of the German Angular book and loves to share knowledge – that's why he writes books and blog posts, speaks at meetups and conferences, does Angular training and works as a consultant in his company \"Angular.Schule\".",
     "groups": ["GDE"]
+  },
+  "johanneshoppe": {
+    "name": "Johannes Hoppe",
+    "picture": "johanneshoppe.jpg",
+    "twitter": "johanneshoppe",
+    "website": "https://angular.schule",
+    "bio": "Johannes works as a software architect and consultant for Angular. He is co-author of the German Angular book and a passionate speaker. With his company \"Angular.Schule\" he offers public Angular training and consulting. Johannes is head of the Angular Meetup in Heidelberg, Germany, and is engaged in a couple of open source projects.",
+    "groups": ["GDE"]
   }
 }