Feature Request: Rendering specific slide in a ratio that is suitable for shared card image

[uriahf]

Hi!

Following @gadenbuie advice I open this issue as a feature request:
Originally posted by @uriahf in gadenbuie/garrickadenbuie-com#115 (comment)

I want to render specific slides as an image for my social cards, @gadenbuie explained how to do it in his blog post but this solution works only for the first slide of the presentation.

I made a small workaround:
I created a new presentation that contains only the desired slide but with the ratio: 191:100 and then I used the code from the mentioned blog post:

https://github.com/uriahf/nb_step_by_step/blob/master/render_image_for_social_card.Rmd

It might be really useful to have a function for that :)

[jhelvy]

Thanks @uriahf, this is a good idea. We already have a slides argument in to_png(), so we could attempt to incorporate that same argument in to_social(). We're working on getting the first version of the package up on CRAN at the moment, so I'll keep this idea here and we can add it to the next version.