ENH: nastranSurfaceWriter: added comment

src/sampling/sampledSurface/writers/nastran/nastranSurfaceWriter.H

@@ -27,6 +27,19 @@ Class
 Description
     A surface writer for the Nastran file format - both surface mesh and fields
 
+    formatOptions
+    {
+        nastran
+        {
+            // From OpenFOAM field name to Nastran field name
+            fields ((pMean PLOAD2));
+            // Optional scale
+            scale 2.0;
+            // Optional format
+            format free;    //short, long, free
+        }
+    };
+
 SourceFiles
     nastranSurfaceWriter.C
     nastranSurfaceWriterTemplates.C