Feature: Citation section at end of README

[stellaprins]

Is your feature request related to a problem? Please describe.

In addition the a cff file with info for people on how to cite k-Wave-II (see #183), do we also want to add a small section at the end of the README.md?

Describe the solution you'd like

I was thinking about:

Citation

k‑Wave‑II builds on a wide range of algorithms developed across many publications.

The standard citation for use of the toolbox is:

Treeby, B. E., Jaros, J., Rendell, A. P., & Cox, B. T. (2012). Modeling nonlinear ultrasound propagation in heterogeneous media with power law absorption using a k-space pseudospectral method. The Journal of the Acoustical Society of America, 131(6), 4324–4336. https://doi.org/10.1121/1.4712021

For a full list of other publications, see the websites for the UCL Biomedical Ultrasound Group and the BUT Supercomputing Technologies Research Group.

Describe alternatives you've considered

No response

Additional context

See issues #183 #235 #236 for more context around References