Add a good, playful and interactive Eco-Score explainer

[teolemon]

What

• Add a good, playful and interactive Eco-Score explainer
• We definitely need to add a good Eco-Score and Nutri-Score one-time explainer in app, beyond what we have for knowledge panels.
• It would require a reflexion:
• is a video good (like the official ones) ?
• Can we have a vertical video (none of them exist to my knowledge) to appear more native ? Should we have something animated by code instead (difficult) ?
• Is text and image enough, and will people actually engage with that little?

See also

• Add a good, playful and interactive Nutri-Score explainer  #3983

Part of

• 🐣 The app should onboard users (Tracker) #561