Update README.md with FHI requirement

README.md

@@ -24,6 +24,9 @@ The reference documentation can be found [here](https://roy.pages.obspm.fr/pFoF)
 pFoF needs:
 * MPI: it has been tested with OpenMPI and IntelMPI
 * HDF5: parallel version with support of Fortran 2003
+* the Fortran HDF5 Interface library compiles with MPI support
+
+Fortran HDF5 Interface is available here: https://gitlab.obspm.fr/roy/fortran-hdf5-interface
 
 It comes with some GNU Make makefiles. You should edit the Make.inc file to edit the options according to your configuration.