Transfer of the repository to JuliaGraphics organization

[kimikage]

cf. https://discourse.julialang.org/t/pre-rfc-ann-color-related-packages-yuvcolortypes-cmykcolortypes-colorprofiles-hdrcolortypes-hdrimages/113032

• Write documents and tests
  • Incomplete parts should be marked with TODO or FIXME.
• Transfer the repo to a member of JuliaGraphics
• Transfer the repo to JuliaGraphics organization
• Configure collaborators (add @kimikage)
• Update CI settings
  • DOCUMENTER_KEY
  • Documenter deploy key
  • CODECOV_TOKEN
• Update repository URL in docs
• Update copyright owner (add "and other contributors")
• Register package