add fields to countries table

[vronk]

add: text field description.

link to website(s) - solved via outreach-table

logo is already a field in countries - currently as string=> just to store URL (logos stored externally as asset)

[stefanprobst]

https://github.com/DARIAH-ERIC/dariah-knowledge-base/blob/main/prisma/schema.prisma#L70-L95

model Country {
  id String @id @default(uuid()) @db.Uuid

  code          String
+ description   String?
  endDate       DateTime? @map(name: "end_date")
  logo          String?
  marketplaceId Int?      @map(name: "marketplace_id")
  name      String
  startDate DateTime?   @map(name: "start_date")
  type      CountryType

  contributions Contribution[]
  institutions  Institution[]
  outreach      Outreach[]
  reports       Report[]
  services      Service[]
  software      Software[]
  users         User[]

  createdAt DateTime @default(now()) @map(name: "created_at")
  updatedAt DateTime @updatedAt @map(name: "updated_at")

  @@index(fields: [code])
  @@map(name: "countries")
}