Example and documentation: Generate social image

[peterpeterparker]

Motivation

In an episode of Juno Live last year we implemented a feature that generate dynamic social images using serverless functions. It would be great to provide some documentation for this pattern.

Resources

• Live stream: https://www.youtube.com/watch?v=E2Ue4jYl_zk

• Source code: https://github.com/peterpeterparker/juno-calendar

Tasks

• Create the simpliest example in the Juno examples repo https://github.com/junobuild/examples/tree/main/rust

• Document an entry in "More examples" of the Rust guide: https://juno.build/docs/guides/rust#more-examples