Include publication in the documentation

Hi @erifarov

Given that we have a publication, we should include it in the documentation:

Pérez-Zanón, N., Ho, A. Chou, C., Lledó, L., Marcos-Matamoros, R., Rifà, E. and González-Reviriego, N. (2023). CSIndicators: Get tailored climate indicators for applications in your sector. Climate Services. https://doi.org/10.1016/j.cliser.2023.100393

• Readme file
• DESCRIPTION file
• earth wiki: https://earth.bsc.es/wiki/doku.php?id=tools:rtools#how_to_cite

Not urgent... just to remind it for the next release.

Thanks,

Núria