Some ideas for improving the library

[kuffmode]

Hi all,
I've been using Netneurotools for a long time and I have some things you can easily add to improve usability.

1. Add a citation instruction. I ended up just writing down the GitHub link, but you can add a Cite this repository using a citation.cff file. Here's an example: https://github.com/kuffmode/YANAT/blob/main/CITATION.cff
2. I would add a check for signed matrices. I remember you can easily pass a signed matrix to communicability that would work and you would end up with a “signed communicability matrix” but as far as I know, negative values don't make sense in these models.
3. Point plot returns a figure that is unnecessary. I ended up tinkering with it so it returns the ax instead. In this case, people can define their own figures the way they want and embedd a point plot wherever they like. Check function brain_plotter here: https://github.com/kuffmode/OI-and-CMs/blob/main/utils.py#L422

If you prefer, I can do these myself and do a pull request. In any case, well done!