DOC Create triage guide in maintainer documentation

As part of talking about triaging at the Scientific Python Summit I realised that we have quite some cumulative experience with triaging. There are also different approaches to things.

As a result I think it would be useful if we create a triaging guide as part of our developer/maintainer documentation. The goal of the guide would be to serve as a reference for what to do as a triager, what tools we have available to help with the process and so on.

Some initial things I can think of including:
* list of labels we have for triaging and what to use them for
* "please don't open a PR before the discussion has converged" as a policy (triagers should close these "early PRs" to help enforce this)
* bookmarked search queries/lists of issues
  * [needs triage](https://github.com/scikit-learn/scikit-learn/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20label%3A%22Needs%20Triage%22)
  * [new PR without reviews](https://github.com/scikit-learn/scikit-learn/pulls?q=is%3Apr+is%3Aopen+review%3Anone+sort%3Acreated-desc)
  * [new PR without reviews by a maintainer](https://github.com/search?q=repo%3Ascikit-learn%2Fscikit-learn+is%3Apr+is%3Aopen+author%3Abetatim+author%3Aogrisel+author%3Aglemaitre+author%3Alesteve+review%3Anone&type=pullrequests&s=created&o=desc)
     * needs more maintainer usernames in the query
     * we could have a similar query for recurring contributors, but how?
  * [PRs waiting for second reviewer](https://github.com/scikit-learn/scikit-learn/pulls?q=sort%3Aupdated-desc+is%3Apr+is%3Aopen+review%3Anone+label%3A%22Waiting+for+Second+Reviewer%22)
  * [Open PRs that you have reviewed in the past](https://github.com/scikit-learn/scikit-learn/pulls?q=sort%3Aupdated-desc+is%3Apr+is%3Aopen+reviewed-by%3A%40me+)
  * look at PRs marked with "autoclose" and decide to potentially remove the label or re-open if the PR has significantly improved [scikit-learn/scikit-learn/issues (sort:updated-desc label:autoclose)](https://github.com/scikit-learn/scikit-learn/issues?q=sort%3Aupdated-desc%20label%3Aautoclose)
* integrate with https://scikit-learn.org/dev/developers/bug_triaging.html#triaging-operations-for-members-of-the-core-and-contributor-experience-teams

Can you think of more search queries that would be useful @lesteve?



xref https://github.com/scientific-python/summit-2025-nov/issues/6

COMMENT:
It would also be nice to see whether "Needs Reproducible Code" and "Needs Info" can be closed from time to time. [GitHub search](https://github.com/scikit-learn/scikit-learn/issues?q=sort%3Aupdated-desc%20is%3Aissue%20state%3Aopen%20label%3A%22Needs%20Info%22%20label%3A%22Needs%20Reproducible%20Code%22)

I went over the "Needs Info" ones a few days ago. There were not that many like ~10.

Rather than unreviewed, it would be nice to have PRs without answer, with the bot comment right now you can filter for [PRs with strictly less than 2 comments](https://github.com/scikit-learn/scikit-learn/issues?q=sort%3Aupdated-desc%20is%3Apr%20comments%3A%3C2%20state%3Aopen)

At the end of the day if you want a bit of flexibility you probably need to do your own dashboard with custom GraphQL queries.

Labels: Documentation