Add automatic documentation deployment pipeline
The automatic documentation deployment shall consist in
- prepare documentation folder docs as in (https://gitlab.com/drb-python/drb/-/tree/main/docs) including
- `conf.py` file to setup sphinx tool
- at least index.rst with a description of the implementation in addition to the proposed template in drb.
- add in `.gitlab-ci.yml` the `page` entry
Contents could be inherited from the README.md, but this file shall stays up-to-date.
issue