Update documentation to ask for citation of the relevant method papers

doc/RTD/source/CitingSWIFT/index.rst

@@ -71,4 +71,8 @@ code. This corresponds to the following bibtex citation block:
      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
    }
 
-
+When using models or parts of the code whose details were introduced in other
+papers, we kindly ask that the relevant work is properly acknowledge and
+cited. This includes the :ref:`subgrid`, the :ref:`planetary` extensions, the
+hydrodynamics and radiative transfer implementations, or the particle-based
+:ref:`neutrinos`.