Describe the solution you'd like

For PRs, I’d like the UI to show a “this is first-time contributor” indicator similar in some way to what the GitHub UI shows.

But if we’re going to show that, it seems like we should just go ahead also always some indicator of the author’s role with respect to the repo to which the PR was submitted. I mean, “contributor”, “member”, “owner” etc.

We can get that author-role data with the API — from the value of the pull_request.author_association field. The values NONE, FIRST_TIMER, or FIRST_TIME_CONTRIBUTOR all basically indicate “first-time contributor”. See the details at https://michaelheap.com/github-actions-check-permission/.

Describe alternatives you've considered
I haven’t considered any alternatives.

Additional context

Use case: I’m one of the core reviewers for MDN Web Docs, and each week we get a significant number of people contributing docs patches to MDN for the first time. In those cases, I like to post a special comment welcoming them and thanking them for their first contribution.

Example: mdn/content#37835 (comment)

And when I have a lot of “Needs My Review” PRs to triage, I personally also like to give some priority to the first-time-contributor PRs over PRs from returning contributors — or minimally, I try to make sure those first-time-contributor PRs don’t sit for too long without me or somebody else taking time to comment, at least just to give them some estimate of when we’ll be able to actually review the PR. And I especially like to make sure that those first-time contributor PRs don’t end going unhandled for so long that a project stale bot ends up auto-closing them

Implementing

I’d be willing to contribute a patch myself — once I get familiar enough with the code to be able to write up patch.

But if somebody else gets it implemented in the meantime, that’d be great too.