Fix NCOMMAS restart_file_tool link

This model does not compile with Manhattan.

models/NCOMMAS/readme.rst

@@ -99,7 +99,7 @@ Overview
      ncommas netCDF restart files into a set of DART files that have a consistent timestamp. If you simply convert each
      ncommas file to a DART file using ``ncommas_to_dart``, each DART file will have a 'valid time' that reflects the
      ncommas time of that state - instead of an ensemble of states reflecting one single time. The
-     `restart_file_utility <../../../utilities/restart_file_utility.f90>`__ can be used to overwrite the timestep in the
+     :doc:`restart_file_tool <../../assimilation_code/programs/restart_file_tool/restart_file_tool>` can be used to overwrite the timestep in the
      header of each DART initial conditions file. The namelist for this program must look something like:
 
    ::