Proposal: notable-changes bot comment for summaries #821

Something I've been thinking about for a while is extending the bot to add a comment whenever the notable changes label is added to a PR in nodejs/node. I haven't tried crafting it, but I'm assuming it'd be possible to implement.

The comment would say something like:

The notable-changes label has been added by _@user.

Please include your text below if you'd like to include a more detailed summary in the changelog.

[Insert here]

Why?

• Releasers don't always have the context to expand on the notable changes - the author(s) are best placed to write these and determine if more detail is warranted.
• Having the notable changes proposed in the PR rather than the release proposal means the text will be consistent between release lines by default.
• Potential to extend our release preparation tooling to automatically pick-up the supplied text.

Proposing this here first to see if @nodejs/release thinks it's a good idea. We'll likely need to propose it more widely.