added survey

prisma/schema.prisma

@@ -55,6 +55,7 @@ model User {
   archiveAsPDF            Boolean               @default(true)
   archiveAsWaybackMachine Boolean               @default(false)
   isPrivate               Boolean               @default(false)
+  referredBy              String?
   createdAt               DateTime              @default(now())
   updatedAt               DateTime              @default(now()) @updatedAt
 }