docs: style guide update (NOAA-GFDL#1642)

Author: thomas-robinson

CODE_STYLE.md

@@ -10,10 +10,15 @@
 * A copy of the [Gnu Lesser General Public License](https://www.gnu.org/licenses/lgpl-3.0.en.html)
   must be included at the top of each file.
 * Documentation should be written so that it can be parsed by [Doxygen](http://www.doxygen.nl/).
+* Files, modules, and public routines should be prefixed with `fms_subfolder_` where `subfolder` is
+  the name of the subfolder that the file is in.  Shorten subfolder names (ie diag) are acceptable
+  as long as they are consistent within the subfolder.
 * All variables should be defined, and include units. Unit-less variables should be marked `unitless`
 * Provide detailed descriptions of modules, interfaces, functions, and subroutines
 * Define all function/subroutine arguments, and function results (see below)
 * Follow coding style of the current file, as much as possible.
+* Add public routines to be used ouside of FMS to the libFMS.F90 file so they can be accessed 
+  through `use FMS`.
 
 ## Fortran
 
@@ -89,7 +94,7 @@
   same include subdirectory as the .fh files.  See below for details.
 ## Fortran Example
 
-```Fortran ./example.F90 file
+```Fortran ./fms_subfolder_example.F90 file
 
 !***********************************************************************
 !*                   GNU Lesser General Public License
@@ -115,55 +120,55 @@
 !! @author <developer>
 !! @email gfdl.climate.model.info@noaa.gov
 
-module example_mod
+module fms_subfolder_example_mod
   use platform_mod, only r4_kind, r8_kind, i4_kind, i8_kind
   use util_mod, only: util_func1
   implicit none
   private
 
-  public :: sub1
-  public :: func1
-  public :: ex_subroutine
+  public :: fms_subfolder_example_sub1
+  public :: fms_subfolder_example_func1
+  public :: fms_subfolder_example_ex_subroutine
 
-  interface ex_subroutine             !< generic interface block.  When the user
-    module procedure ex_subroutine_r4 !! calls ex_subroutine, the compiler checks
-    module procedure ex_subroutine_r8 !! the input arguments and invokes either
-  end interface ex_subroutine         !! ex_subroutine_r4 or ex_subroutine_r8
-                                      !! ex_subroutine_r4/8 are generated by the preprocessor
-                                      !! which requires example_r4.fh, example_r8.fh, and
-                                      !! example.inc files
+  interface fms_subfolder_example_ex_subroutine !< generic interface block.  When the user
+    module procedure ex_subroutine_r4        !! calls ex_subroutine, the compiler checks
+    module procedure ex_subroutine_r8        !! the input arguments and invokes either
+  end interface ex_subroutine                !! ex_subroutine_r4 or ex_subroutine_r8
+                                             !! ex_subroutine_r4/8 are generated by the preprocessor
+                                             !! which requires example_r4.fh, example_r8.fh, and
+                                             !! example.inc files
 
   !> @brief Doxygen description of type.
-  type,public :: CustomType
+  type,public :: fms_subfolder_example_CustomType
     private
     integer(kind=i4_kind) :: a_var !< Inline doxygen description.
     real(kind=r8_kind),dimension(:),allocatable :: b_arr !< long description
                                                          !! continued on
                                                          !! multiple lines.
-  endtype CustomType
+  endtype fms_subfolder_example_CustomType
 
   contains
 
   !> @brief Doxygen description.
-  subroutine sub1(arg1, arg2, &
+  subroutine fms_subfolder_example_sub1(arg1, arg2, &
     & arg3)
     real(kind=r4_kind),intent(in) :: arg1 !< Inline doxygen description.
     integer(kind=i8_kind),intent(inout) :: arg2 !< Inline doxygen description.
     character(len=*),intent(inout) :: arg3 !< Long inline doxygen
                                            !! description.
 
     arg1=2.456_r4_kind
-  end subroutine sub1
+  end subroutine fms_subfolder_example_sub1
 
   !> @brief Doxygen description
   !! @return Function return value.
-  function func1(arg1, arg2) result(res)
+  function fms_subfolder_example_ func1(arg1, arg2) result(res)
     integer(kind=i4_kind),intent(in) :: arg1 !< Inline doxygen description
     integer(kind=i4_kind),intent(in) :: arg2 !< Inline doxygen description
     integer(kind=r8_kind) :: res
 
     res=real(arg1,r8_kind) * 3.14_r8_kind
-  end function func1
+  end function fms_subfolder_example_func1
 
 #include "example_r4.fh" !< These two header file contains the macro definition
 #include "example_r8.fh" !! and an "#include example.inc" where the procedure