feat: add a feature for redirecting users on signing

Signed-off-by: Adithya Krishna <adi@documenso.com>

packages/prisma/schema.prisma

@@ -166,6 +166,7 @@ model DocumentMeta {
   dateFormat String?  @db.Text @default("yyyy-MM-dd hh:mm a")
   documentId Int      @unique
   document   Document @relation(fields: [documentId], references: [id], onDelete: Cascade)
+  redirectUrl String? @db.Text 
 }
 
 enum ReadStatus {