README is outdated since version 1.0.0

[tifuchs]

The README needs to be updated.

• Many features described as planned in the README are already implemented.
• Should add a screenshot of the GUI or a short gif illustrating some features of the software
• README should advertise and give a short quick start guide, but not documentation.
• Documentation should be moved to a documentation page: we have to decide what to use (readthedocs?)