message: [skip ci] Update version creation and new changelog file
diff: @@ -6,6 +6,16 @@ git clone https://github.com/GUDHI/gudhi-devel.git
  cd gudhi-devel
  ```
  +## Release note
  +
  +Verify that [.github/next_release.md](.github/next_release.md) is up-to-date with the development performed on the release.
  +Also check [.github/change_log.md](.github/change_log.md) is appended with the release note.
  +
  +## Unlabelled issues and pull requests
  +
  +Check there are no [unlabelled closed issues](https://github.com/GUDHI/gudhi-devel/issues?q=is%3Aissue+is%3Aclosed+no%3Alabel)
  +nor [unlabelled closed PRs](https://github.com/GUDHI/gudhi-devel/pulls?q=is%3Apr+is%3Aclosed+no%3Alabel) related to the release.
  +
  ## Version file modification
  **Edit the file CMakeGUDHIVersion.txt**, and increment major, minor, or patch version number, in function of the version new delivery.
  @@ -127,3 +137,9 @@ docker image on docker hub.
  Send version mail to the following lists :
  * gudhi-devel@inria.fr
  * gudhi-users@inria.fr (not for release candidate)
  +
  +## File to update after the release
  +
  +**Edit the file CMakeGUDHIVersion.txt**, and increment major, minor, or patch version number, in function of the future version (something like `3.X+1.0a0`).
  +
  +Reset [.github/next_release.md](.github/next_release.md) with [.github/for_maintainers/next_release_template.md](.github/for_maintainers/next_release_template.md).
  \ No newline at end of file
  