[Packaging] - Setting up the repository

[garciagenrique]

• [x] Set up the repository to follow a gitflow workflow (every new features is pushed to dev, and merged to main via Pull Requests)
• [x] Integrate/merge #1 into the repository
• [x] Add a README.md file with the minimum instruction on how to
  • [x] Set up an environment
  • [x] Install, build and test the extension
• [x] Set up a minimal CI/CD (no need of all the stages that comes with the tutorial, for the moment)
• [x] Get familiarised with Licenses and #3