Releasing: Add a 'git push' to point release, adjust MD formatting

[hugovk]

A couple of minor fixes after doing the 8.0.1 release.

---

Add an explicit git push after the cherry pick.

• Cherry pick individual commits from master branch to release branch e.g. 5.2.x, then git push.

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This bit renders fine in https://github.com/python-pillow/Pillow/blob/master/RELEASING.md:

* [ ] Check [GitHub Actions](https://github.com/python-pillow/Pillow/actions),
      [Travis CI](https://travis-ci.org/github/python-pillow/Pillow) and
      [AppVeyor](https://ci.appveyor.com/project/python-pillow/Pillow) to confirm
      passing tests in `master` branch.

But not so well when pasted into release issues (#4764):

• Check GitHub Actions,
  Travis CI and
  AppVeyor to confirm
  passing tests in master branch.

So stick it all on one line:

• Check GitHub Actions, Travis CI and AppVeyor to confirm passing tests in master branch.