Fix link to example JSON dataset in API docs

[vera]

What this PR does / why we need it:

I noticed that this link text on https://guides.dataverse.org/en/latest/api/native-api.html#create-dataset-command is not correct.

Which issue(s) this PR closes:

Special notes for your reviewer:

Suggestions on how to test this:

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

Is there a release notes update needed for this change?:

Additional documentation:

[pdurbin]

I just previewed this at https://guides.dataverse.org/en/latest/api/native-api.html#create-a-dataset-in-a-dataverse-collection and it look great! It says...

(dataset-finch1_fr.json is a variant of this file that includes setting the metadata language (see :MetadataLanguages) to French (fr).

This is much better than what we have at https://guides.dataverse.org/en/5.12.1/api/native-api.html#create-a-dataset-in-a-dataverse-collection which says.

(dataset-create-new-all-default-fields.json is a variant of this file that includes setting the metadata language (see :MetadataLanguages) to French (fr).

Merging! Thanks, @vera!