#161: Set default value for createdAt field, store zone chats into database

prisma/schema/schema.prisma

@@ -11,7 +11,7 @@
 // npx prisma migrate deploy
 
 generator client {
-  provider = "prisma-client-js"
+  provider        = "prisma-client-js"
   previewFeatures = ["prismaSchemaFolder"]
 }
 
@@ -27,5 +27,5 @@ model Chat {
   zoneId      Int
   zone        Zone      @relation(fields: [zoneId], references: [id], onDelete: Cascade)
   message     String
-  createdAt   DateTime
+  createdAt   DateTime  @default(now())
 }