Merge r2readthedocs and altdoc

[etiennebacher]

Add two functionalities of r2readthedocs in altdoc:

• use sphinx documentation generator
• add option to pull the documentation from package dependencies to have a self-contained website (e.g ropensci-review-tools)

@mpadge Feel free to add anything you want about the merge process here: potential issues, functionalities that I forgot to mention, etc.

[etiennebacher]

altdoc 0.1.0 is on CRAN. I will now try to focus a bit more on these two functionalities.

[vincentarelbundock]

AFAICT, this uses restructuredtext, so it's quite a bit different than the Markdown/Quarto based generators we currently use. It's likely to require a very different infrastructure.

Are there very compelling reasons to prefer this over our current generators?

If not, I'd close this as out of scope.

[etiennebacher]

The objective was to gather several packages in a single website, like the ropensci-review-tools. The advantages of doing so are listed in the README of r2readthedocs.

Agreed it's quite out of scope for now, maybe we can go back to this later when the rest is well stabilized

[mpadge]

Yes, r2readthedocs is indeed all based on .rst, so not compatible with quarto in current form. I'm happy for this to be closed for now, but will keep an eye on altdoc developments. Thanks!