Link to a issue in another repo

[gregoriopellegrino]

Is your feature request related to a problem? Please describe.
I should report an issue in a document, the problem is that the issue is from a different repository from that of the document.

Describe the solution you'd like
Have the ability to link to issues external to the document repository.

Describe alternatives you've considered
Enter a generic note.

Can you or your organization fund the work or help with development?
Sorry, I don't think so.

[sidvishnoi]

Can't give a timeline, but we're already tracking it in #3433.