CLN: Delete pandas-docs GitHub organization
xref #41050

Feels like https://github.com/pandas-docs/pandas-docs-travis was created to publish the development pandas docs, but that was eventually moved elsewhere, and now there is just a two year old copy published there (in their github pages).

I think we should delete the `pandas-docs` organization, to avoid confusion, or people accessing old docs from outdated links to that copy.