Add a thumbnail to every blog post

[realjuangalt]

• Generate them with app.leonardo.ai
• ideally using "cypherpunk color scheme has orange instead of purple lighting, add organic tones and nature in the background, optimistic futurism" at the end of the thumbnail idea to keep style
• try to produce it in 4:3 aspect ratio,
• ideally in webp format which can be easily produced from a jpg or png via https://www.photopea.com/