create sendMessage(subscribe)

 type Subscription {
 type Subscription {
-  sendMessage(message: String!): Message!
+  sendMessage: Message
 }
 }

-import { prisma } from "../../../utils";
+import { isAuthenticated, prisma } from "../../../utils";
+import { NEW_MESSAGE_TOPIC } from "../../../topics";
 
 
 export default {
 export default {
   Subscription: {
   Subscription: {
-    sendMessage: async (_, args) => {
-      const { message } = args;
+    sendMessage: {
+      subscribe: async (_, __, { request, pubsub }) => {
+        pubsub.asyncIterator(NEW_MESSAGE_TOPIC);
+      },
     },
     },
   },
   },
 };
 };