[other] OG image generation

[Th1nkK1D]

Idea

• Use Nuxt's dynamic route with promise id param
• Use a headless browser script to take a screenshot. Example here
• Add to existing promise page

Depends on

• #15

• 22

[Th1nkK1D]

Actually, the issue is simpler than that. The images have static variation in each status, no need to dynamically generate images. Just need to dynamically generate HTML for each promise.