Also send room members' presence in per-room initialSync

swagger/client-server/api-docs-rooms

@@ -970,6 +970,14 @@
           "items": {
             "$ref": "Event"
           }
+        },
+        "presence": {
+          "type": "array",
+          "description": "A list of m.presence events representing the current presence state of the room members.",
+          "required": false,
+          "items": {
+            "$ref": "Event"
+          }
         }
       }
     }