docs/intro.md doesn't exist anymore

[Lennart]

This very promising link in the README.md with a 'quick introduction', isnt working anymore
https://github.com/xebia-functional/xef?tab=readme-ov-file#-quick-introduction

It got removed earlier (for being outdated)
1d64269

Is there another 'quick introduction somehwere else, maybe?

[José Carlos Montañez]

Thanks for seeing that 👍