Describe the feature or problem you’d like to solve

If I have a configured remote named <remote> in my Git repository and want to open a PR against that remote, I'd like to able to do

gh pr create -R <remote>

but right now I have to do

gh pr create -R <github-user-or-org>/<repo-name>

which can be considerably longer depending on the project.

Proposed solution

How will it benefit CLI and its users?

This will allow them to type less :)

Additional context

This ideally would work for every gh command accepting a -R argument, when run from inside a Git repository.