Improve communication with contributors on the issue tracker and PRs (Language summit follow up)

[ezio-melotti]

@iritkatriel

I don’t know whether it’s better to add an “acknowledged” label or an “unacknowledged” label that gets added to all new issues and is later removed.

I prefer the latter: add the label by default to new issues and have a triager remove it after looking at it. This has some advantages:

• it’s easy to search for issues that need attention
• it’s easier to remove the label than adding it
• it doesn’t add an extra label to all open issues

A triager can decide to leave the label (or even add it back), if they are not confident about the status and/or validity of issue. For example, they can ping the expert and let them remove the label after assessing the validity of the issue, or add it back on an old issue that might no longer be valid.