Explain RO-Crate support better in the guides

[pdurbin]

In the following pull request...

• Add RO-Crate to guides #10796

... at least made it possible for someone searching for "RO-Crate" in our guides to find that Dataverse has some support for it, but we also should link to the page that @beepsoft showed me, at least: https://www.researchobject.org/ro-crate/dataverse

I looked it over and made a few tweaks to it here:

• clarify Dataverse vs Harvard Dataverse, other tweaks ResearchObject/ro-crate#500

@beepsoft @ErykKul @okaradeniz @DieuwertjeBloemen, you've all worked on RO-Crate stuff. Do you have any suggestions on where to put this link in the guides? Please feel free to make a PR!

[pdurbin]

I'm not sure if https://www.researchobject.org/ro-crate/blog/2025-10-13/dataverse-cedar-and-ro-crate-the-building-blocks-of-arp belongs in the guides or not but it's a good read, by @beepsoft.

[pdurbin]

At the very least, we should add RO-Crate to this new PR where we are putting the list of features in the guides:

• move the list of features into the guides #12000

[okaradeniz]

I just had a look at the PR, maybe it could be added somewhere around ## External tools? For example:

## RO-Crate support 

Dataverse supports RO-Crate through external tools, previewers and exporters. {ref} More information <https://www.researchobject.org/ro-crate/dataverse>.