This document summarizes the steps that are required to add a new diagnostic
to MPAS-Atmosphere. The "tempate" files may be used as a guide for what is
generally required to implement a diagnostic.

1) Define namelist options, dimensions, packages, and fields needed by 
   the diagnostic in a new Registry_<your_diagnostic>.xml file. 

   Add a #include statement for this new Registry file in 
   Registry_diagnostics.xml.

2) Create a new module for the diagnostic; the "mpas_atm_diagnostic_template.F" 
   module file may be used as a template.

3) Add calls to the diagnostic's "setup", "update", "compute", "reset", and 
   "cleanup" routines in the main diagnostic driver. Note that some diagnostics
   may not require all of these routines, in which case they can simply be
   omitted.

3) Add the object file for the new diagnostic module to the definition of 
   DIAGNOSTIC_MODULES in the Makefile, and add a dependency on the new module 
   for the diagnostic driver. If the diagnostic has any other dependencies
   within the diagnostics/ subdirectory, specify those as well in the Makefile.
