Setup github action CI/CD for the PyGreece discord bot

[thepetk]

Issue description

This issue focuses on the CI/CD part of the discord bot. More detailed a new workflow is required in order to push the new code to the server running the bot after a successful merge to the main branch of the repo.

The pipeline should create & push a new image tag upon every PR merge to a registry. After the successful push a new deployment of the discord bot should be made.

In case of a image build or deployment failure the workflow should notify a specific channel inside the discord server.

Acceptance Criteria

• A new workflow has been created which takes care of the CI/CD part.
• Notification alerts should be included for failures.

[lysnikolaou]

@gzisopoulos I'm taking the issue assignment off since this has become stale and in case people want to work on it during OpenConf.