Updated instructions for version tag creation.

How to create a version tag

===========================

Example for tag "v2.11".

Example for tag "v2.12".

1. Update file formatting following conventions.

   b. Update the source file `doc/source/history.rst <../../source/history.rst>`_ of this chapter.

   c. Change the release tag that will be shown in the documentation in the file

      `doc/source/conf.py <../../source/conf.py>`_::

   c. Change the release tag that will also be imported to the documenation in the `pyproject.toml <../../../pyproject.toml>`_ file::

        # The full version, including alpha/beta/rc tags

        release = "v2.11"

        release = "2.12"

   d. Commit and push these changes::

       git commit -m 'Defined v2.11' .

       git commit -m 'Defined v2.12' .

       git push

4. Tag and push the code to the git repository::

      git tag -a 'v2.11' -m 'Tagged v2.11'

      git push origin v2.11

      git tag -a 'v2.12' -m 'Tagged v2.12'

      git push origin v2.12