Update docs

[ffelten]

Description

Add arxiv badge, update notebook

Fixes # (issue)

Type of change

Please delete options that are not relevant.

• [Documentation only change (no code changed)

Checklist:

• I have run the pre-commit checks with pre-commit run --all-files
• I have run ruff check . and ruff format
• I have run mypy .
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• 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