Cookiecutter: add 2023 to copyright and clarify tutorial to be added

[bobleesj]

• URLs work, doc compiles

Is there a paper for snmf ? @sbillinge ?

In the next PR, I will make a PR from cookie to main for doc hosting.

[sbillinge]

@bobleesj yes, there is a paper to cite

[bobleesj]

@bobleesj yes, there is a paper to cite

@sbillinge Which is it? can't find one co-authored by you.

[sbillinge]

Ran Gu, Yevgeny Rakita, Ling Lan, Zach Thatcher, Gabrielle E. Kamm, Daniel O’Nolan,
Brennan Mcbride, Allison Wustrow, James R. Neilson, Karena W. Chapman, Qiang Du, and Simon
J. L. Billinge. “Stretched Non-negative Matrix Factorization”. In: arXiv (2023). arXiv:2311.15173
[cond-mat.mtrl-sci]. url: http://arxiv.org/abs/2311.15173

It has been accepted in npj computational materials but not sure if it has appeared yet. It is better to put the published version in.

[bobleesj]

It has been accepted in npj computational materials but not sure if it has appeared yet. It is better to put the published version in.

I did a quick Google/Scholar search, but couldn't find one.

I made an issue to replace them later: Modify publication link from arXiv to peer-reviewed publication when available #65