Update README.rst

README.rst

@@ -40,7 +40,7 @@ The Python script has help for the arguments::
 
     $ python3 generator.py -h
     usage: generator.py [-h] [-s SOURCE_DIR] [-j JSON_PATH] -g CASTXML_PATH
-                        [--includes INCLUDES] [--no-generation]
+                        [--includes INCLUDES] [--no-generation] [--config-path CONFIG_DIR]
 
     optional arguments:
       -h, --help            show this help message and exit
@@ -54,6 +54,8 @@ The Python script has help for the arguments::
       --includes INCLUDES, -i INCLUDES
                             Path to the includes directory.
       --no-generation, -n   Only print name of files to be generated
+      --config-path CONFIG_DIR, -cg CONFIG_DIR
+                            config file path
 
 
 To run over the entirety of the local example, we use a command like this::