Test Documentation with doctest - Usage guide is broken for version 1.x

[cleder]

The examples in the Usage guide are no longer working with version 1.0 -> #100

This is because the syntax is still python 2 and that the API has changed from version 0.x to 1.x.

Test the documentation with doctest

cd docs
make html
python -m doctest -v _build/html/_sources/usage_guide.rst.txt

...
1 items had failures:
  14 of  32 in usage_guide.rst.txt
32 tests in 1 items.
18 passed and 14 failed.
***Test Failed*** 14 failures.

Todo:

1. Update python syntax to python 3
2. Fix the failing test for the new API
3. Run the doctests in GitHub action

[cleder]

Work on Branch

[cleder]

https://www.b-list.org/weblog/2023/dec/10/python-doctest/ https://abstraction.blog/2023/11/22/intuitive-documentation-strategy