add documentation about the new changelog update hook, refs #9896
add an example script and also the code for the hook, refs #9896
Merge branch 'master' into 9896-changelog-file

* master:
  Update Changelog
  Add Changelog
  Delete CHANGELOG.md
  Update Changelog
  Update Changelog
  Add Changelog
  Bump VERSION file
  Bump VERSION file
  Bump VERSION file
  Bump VERSION file
  Bump VERSION file
  Add VERSION file
  Delete VERSION
  Add VERSION file
Merge pull request #4 from ninech/9896-changelog-file

Hook for updating a changelog file