Provide DocumentationLink of ComponentSet in Figma API

Currently, Figma API doesn’t provide documentation link information of ComponentSets (sets of component variants) while it is possible to give one to them in the Figma UI.
In a Figma file, the document link of a component set goes down to its children variants unless they have their own. It is a convenient way to give all the variants the same reference link.
The same logic should be applied to the Figma API, or at least, it should provide “DocumentationLink” field to ComponentSet too.