Update documentation and changelog

ChangeLog

@@ -13,6 +13,8 @@ Release date: TBA
 
   Closes #4405
 
+* scm_setuptools has been added to the packaging.
+
 
 What's New in Pylint 2.8.1?
 ===========================

doc/release.md

@@ -7,11 +7,8 @@ So, you want to release the `X.Y.Z` version of pylint ?
 1. Run the acceptance tests to see if everything is alright with this release. We don't
    run them on CI: `pytest -m acceptance`
 2. Check if the dependencies of the package are correct
-3. Update `__version__` in `pylint/__pkginfo__.py`, `dev_version` should be `None` when
-   you tag, except if it's an alpha release.
-4. Put the version numbers, and the release date into the changelog
-5. Put the release date into the `What's new` section.
-6. Generate the new copyright notices for this release:
+3. Put the release date into the changelog and `What's new` section.
+4. Generate the new copyright notices for this release:
 
 ```bash
 pip3 install copyrite
@@ -21,17 +18,17 @@ git --aliases=.copyrite_aliases . --jobs=8
 # automatically
 ```
 
-7. Submit your changes in a merge request.
+5. Submit your changes in a merge request.
 
-8. Make sure the tests are passing on Travis/GithubActions:
+6. Make sure the tests are passing on Travis/GithubActions:
    https://travis-ci.org/PyCQA/pylint/
 
-9. Do the actual release by tagging the master with `pylint-X.Y.Z` (ie `pylint-1.6.12`
-   for example). Travis should deal with the release process once the tag is pushed with
-   `git push origin --tags`
+7. Do the actual release by tagging the master with `pylint-X.Y.Z` (ie `pylint-1.6.12`
+   or `pylint-4.0.0a1` for example). Travis should deal with the release process once
+   the tag is pushed with `git push origin --tags`
 
-10. Go to github, click on "Releases" then on the `pylint-X.Y.Z` tag, choose edit tag,
-    and copy past the changelog in the description.
+8. Go to github, click on "Releases" then on the `pylint-X.Y.Z` tag, choose edit tag,
+   and copy past the changelog in the description.
 
 ## Manual Release
 
@@ -77,8 +74,3 @@ known at that time, we should use `Undefined`.
 
 If it's a major release, create a new `What's new in Pylint X.Y+1` document Take a look
 at the examples from `doc/whatsnew`.
-
-### Versions
-
-Update `__version__` to `X.Y+1.0` or `X.Y.Z+1` in `__pkginfo__`. `dev_version` should
-also be back to an integer after the tag.