Update 04-presentations.Rmd

[apreshill]

Added link to pandoc manual on slideshows, searching for the previous text led to a dead link

[cderv]

Thanks !

I just need to check for the pdf book if we can provide link this way or if it must be with a replacement text.

I'll merge after I check just to be sure.

[yihui]

if we can provide link this way or if it must be with a replacement text

Either way is fine to me. I'm okay with bare links as long as they don't cause text overflow problems (sometimes a URL can't be broken properly).

Thanks!

[cderv]

Either way is fine to me. I'm okay with bare links as long as they don't cause text overflow problems (sometimes a URL can't be broken properly).

I'll check that then !