Automatic versioning through Github actions

[juice500ml]

• What kind of change does this PR introduce? (Language addition, bug fix, feature, docs update, ...)
  Follow-up of Add CI for automated Python package release #212.
  Add CI for automated Python package release.

• What is the current behavior? (You can also link to an open issue here)
  We have to manually release the package.

• What is the new behavior (if this is a feature change)?

• We want to automatically release the package.
• https://www.conventionalcommits.org/en/v1.0.0/
• https://python-semantic-release.readthedocs.io/en/stable/configuration/automatic-releases/github-actions.html#gh-actions-examples
• https://guicommits.com/semantic-release-to-automate-versioning-and-publishing-to-pypi-with-github-actions/

• Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
  No.
  However, contributors should be now knowledgable about commit conventions.
  I will describe commit convention also.