Feature/#274 improve rtd doc

[maike93he]

Examples from the documentation (Minimum working exampes and Usage details) are now automatically tested within the notebook 'edisgo_documentation_examples.ipynb' which is integrated in test_examples.py

Fixes #274

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• New and adjusted code is formatted using the pre-commit hooks
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[birgits]

@maike93he I don't quite understand what is done in this PR. Where can I find the edisgo_documentation_examples.ipynb?

[maike93he]

@birgits sorry, the python notebook wasn't commited because it was untracked. The notebook - which contains examples from the documentation - is integrated in the test_examples.py file to automatically test the examples from the doc.