[Doc]: Bond associated

[CWillberg]

What is currently missing in the documentation?

I am missing the paper refering to the bond associated implementation.

Can you share related references or the speficic functions you want to document?

No response

Would you be willing to submit a PR?

Yes

[CWillberg]

The paper can be found here https://link.springer.com/article/10.1007/s42102-020-00039-6
I will update the documentation as well