[Doc]: Link to citation page in read me broken

[samGreer]

Documentation Link

https://github.com/matplotlib/matplotlib/blob/main/README.md

Problem

The link at the bottom of the read me is broken and goes to a page not found.

Suggested improvement

Revert to the previous link (https://matplotlib.org/stable/users/project/citing.html). Alternatively, the site could be updated so that the link works, but I don't think that that is possible from the GitHub.

[samGreer]

I've submitted a pull request with the first suggested improvement, it can be found here: #27783

[story645]

Duplicate of #27746