Update the "User guide" vignette

[etiennebacher]

There a bunch of things in {comment} chunks in this vignette because they weren't implemented at the time. I think a lot of them are now available so it would be good to refresh this vignette (it would also allow us to have a few examples of what's missing)

@vincentarelbundock since you created this vignette, do you want to update it? No pressure on this ofc

[vincentarelbundock]

Thanks for the tag. In principle I'm interested, but frankly I'm unlikely to have time.in the next 2-3 months. Ill try to come back to it if/when I can but can't really commit, sorry.