[jni]

References and relevant issues

Relevant previous discussion is in Zulip.

Description

This PR proposes moving the release notes generation from a separate repo to
this one. The motivation is as follows:

• When creating release notes, one has to maintain both a highlights section in
  napari/napari-release-tools and the full documentation update in this repo.
• One then gets suggestions in the docs repo PR or subsequent PRs that then
  need to be backported to the additional notes in the docs repo.
• Additionally, running the script is a bit cumbersome because one needs to
  specify the output directory, which is different for each release manager, so
  it can't be generalised in the script.

Moving the tooling and notes here makes it easier to keep everything in sync,
and also allows the script to have default values for the file paths, and it
then becomes easier to run with
uv run tools/generate_release_notes.py <milestone>
and no further arguments.

See the new README for more details.

• Move generate release notes script to docs repo
• Add additional needed files for release script
• Improve spacing on docstring
• Hard wrap lines for better printing on terminals
• Remove the old script docstring from the module
• raise -> raise from to please linter
• Add README