Add in code all the licenses and attributions for the 3D models

[jscastro76]

Threebox version 2.1.9:

• Eiffel Tower, Custom
• Liberty Statue, CC
• Space Needle, CC
• Radar, NASA Not specified
• Plane, CC
• Soldier, not specified, Attribution to Mixamo
• Windmill, CC
• Elephant, CC-NC
• Dinosaur, CC-NC
• Vehicles, Royalty Free

[jscastro76]

3D models attributions

- Eiffel Tower
  - Creative Commons License attribution:  Eiffel Tower model by https://www.cgtrader.com/lefabshop
  from https://www.cgtrader.com/items/108594/download-page

- Elephant
  - Creative Commons NonCommercial License attribution: Asian Elephant low poly model by https://sketchfab.com/jeremielouvetz
  from https://sketchfab.com/3d-models/asian-elephant-2aeeb8958bc64240962b093705abffdf

- Liberty Statue
  - Creative Commons License attribution: Liberty statue model by https://sketchfab.com/hellolucy2 
  from https://sketchfab.com/3d-models/ellis-island-3cd765a23c5c4c7087acd00624d30590

- Plane 
  - Creative Commons License attribution: Plane model by https://sketchfab.com/ideehochzwei
  from  https://sketchfab.com/3d-models/plane-aa001f5a88f64b16b98356c042f2d5f3

- Radar
  - Attribution, no License specified: Model by https://github.com/nasa/ 
  from https://nasa3d.arc.nasa.gov/detail/jpl-vtad-dsn34

- Soldier
  - Attribution: Soldier animated model by T. Choonyung at https://www.mixamo.com
  from https://www.mixamo.com/#/?page=1&query=vanguard&type=Character

- Space Needle
  - Creative Commons License attribution: Space Needle model by https://sketchfab.com/microsoft
  from https://sketchfab.com/3d-models/space-needle-1d1325bc1ad745dd9eb34fc76e8f6e87

- Triceratops
  - Creative Commons NonCommercial License attribution: Dino low poly model by https://sketchfab.com/Blender_Fox1234
  from https://sketchfab.com/3d-models/triceratops-lowpoly-76beb95d0b5b41a3aae0d07c3eae99fa

- Truck & Car
  - Royalty Free License: Vehicles by https://www.cgtrader.com/antonmoek
  from https://www.cgtrader.com/free-3d-models/car/concept/cartoon-low-poly-city-cars-pack

- Windmill
  - Creative Commons License attribution: Windmill animated model by https://sketchfab.com/data3anshow
  from https://sketchfab.com/3d-models/windmill-animated-6ce5667e8d5c47068ea13196036efd52