Documentation page showing differences between format differences between the Wikibase REST API and Action API currently omits the elaboration on sitelinks structure.
It should be displayed to demonstrate the differences:

• omitting the redundant site ID,
• and always displaying the page URL

in "value" object used by Wikibase REST API.

Task breakdown notes:

• T321483 documents simplifying the sitelinks structure
• the url property has been added via T330252
• add a new sitelinks section to the "Differences in the JSON data format between Wikibase REST API and ActionAPI" doc.