Sect. 3 (Lifecycle of a Pull Request) does not mention Misc/NEWS.d/next and blurb

[jwuttke]

The explanations how to create a pull request are incomplete. They should mention

• That in general a news file is requested.
• How this file can be generated using blurb.
• Under which conditions the "skip news" label can be set.

[methane]

blurb and news entry are described in https://devguide.python.org/committing/#updating-news-and-what-s-new-in-python

Maybe, it's old workflow. Contributor writes patch without news. Core developer commit the patch with news.

In current workflow, we ask contributors to write news entry. So let's move the section from "16. Accepting Pull Requests" to "3. Lifecycle of a Pull Request".