Feature summary (what you would like to be able to do and where): Include Wikifunctions pages as part of the interwiki links available from Wikidata.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
*Go to a page on an WMF wiki that has an equivalent on WIkifunctions (e.g. https://outreach.wikimedia.org/wiki/Main_Page)
*Look at the interwiki links on the associated Wikidata item (in this case, https://www.wikidata.org/wiki/Q5296)
*Note that the equivalent page for Wikifunctions is not listed (in this case, https://www.wikifunctions.org/wiki/Wikifunctions:Main_Page)

Benefits (why should this be implemented?): Basic interoperability of all WMF wikis

See also (e.g.) T138332 and T171140.

Possibly related or parent task: T342865