Replace cheyenne with derecho in a .rst file

doc/source/lilac/obtaining-building-and-running/obtaining-and-building-ctsm.rst

@@ -29,9 +29,9 @@ Obtain CTSM by running::
   ./bin/git-fleximod update
 
 Then build CTSM and its dependencies. On a machine that has been ported to CIME, the
-command will look like this (example given for NCAR's ``cheyenne`` machine)::
+command will look like this (example given for NCAR's ``derecho`` machine)::
 
-  ./lilac/build_ctsm /glade/scratch/$USER/ctsm_build_dir --machine cheyenne --compiler intel
+  ./lilac/build_ctsm /glade/scratch/$USER/ctsm_build_dir --machine derecho --compiler intel
 
 and then, before building the atmosphere model::
 
@@ -145,13 +145,13 @@ the `CIME documentation`_.
 Building on a CIME-supported machine
 ------------------------------------
 
-If you are using a machine that has been ported to CIME_ (for example, NCAR's ``cheyenne``
+If you are using a machine that has been ported to CIME_ (for example, NCAR's ``derecho``
 machine), then you do not need to specify much information to ``build_ctsm``. In addition,
 in this case, CIME will load the appropriate modules and set the appropriate environment
 variables at build time, so you do not need to do anything to set up your environment
 ahead of time. **Building CTSM with LILAC requires ESMF. ESMF is currently an optional
 CIME dependency, so many CIME-ported machines do not provide information on an ESMF
-installation. NCAR's cheyenne machine DOES provide ESMF, but for other machines, you may
+installation. NCAR's derecho machine DOES provide ESMF, but for other machines, you may
 need to add this to your CIME port.**
 
 To build CTSM and its dependencies in this case, run::
@@ -231,7 +231,7 @@ Example usage for a Mac (a simple case) is::
 
   ./lilac/build_ctsm ~/ctsm_build_dir --os Darwin --compiler gnu --netcdf-path /usr/local --esmf-mkfile-path /Users/sacks/ESMF/esmf8.0.0/lib/libO/Darwin.gfortranclang.64.mpich3.default/esmf.mk --max-mpitasks-per-node 4 --no-pnetcdf
 
-Example usage for NCAR's ``cheyenne`` machine (a more complex case) is::
+Example usage for NCAR's ``derecho`` machine (a more complex case) is::
 
   module purge
   module load ncarenv/1.3 python/3.7.9 cmake intel/19.1.1 esmf_libs mkl