Add data migration to add logo to ERDF guides
user
```ruby
slugs = [
  'erdf-programmes-and-resources',
  'erdf-programmes-progress-and-achievements',
  'applying-for-erdf-funding',
  'erdf-national-guidance',
  'previous-erdf-programmes-retaining-documents',
  'european-territorial-cooperation-programmes',
  'reuniting-europe-programme-turkey'
]
logo_url = "https://assets.digital.cabinet-office.gov.uk/government/assets/erdf-logo.png"

puts "Adding logos to ERDF editions"
slugs.each do |slug|
  document = Document.find_by(slug: slug)
  latest_published_edition = document.editions.latest_published_edition.first
  draft_edition = document.editions.latest_edition.draft.first

  puts "Updating logo in #{slug} published version"
  latest_published_edition.update_column(:logo_url, logo_url)

  if draft_edition
    puts "Updating logo in #{slug} draft version"
    draft_edition.update_column(:logo_url, logo_url)
  end
end
```
assistant