[w-tusche]

Changes proposed in this Pull Request

Update the origin / funding links in README.rst and doc/index.rst. Most of them are dead or now point to unrelated content or, one project page now pointsto a site that explains a special kind of gambling.

• Renewable Energy Group at FIAS: group page is gone (404, no archived copy). Link removed, name kept.
• FIAS: now links to fias.institute (old domain redirects there).
• CoNDyNet: condynet.de now belongs to a site explaining some kind of gambling. Exchanged with links to a Wayback Machine snapshot from 2021 regarding the original project page.
• Stromnetze Research Initiative: project page redirects to a generic news page. Exchanged with links to a Wayback Machine snapshot from 2019.
• BMBF: old page is 404, ministry is now BMFTR. Links to the BMFTR site, name "BMBF" kept as it was the funder at the time.

As the project origin an credits are presented this might be check thoroughly.

Checklist

• Code changes are sufficiently documented; i.e. new functions contain docstrings and further explanations may be given in doc.
• Unit tests for new features were added (if applicable).
• Newly introduced dependencies are added to environment.yaml, environment_docs.yaml and setup.py (if applicable).
• A note for the release notes doc/release_notes.rst of the upcoming release is included.
• I consent to the release of this PR's code under the MIT license.

[euronion]

Thanks!