Change stderr/stdout suppress from None to False

src/documentation/Targets_and_Actions.ipynb

@@ -790,7 +790,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Option `stdout` is applicable to script-executing actions such as `bash` and `R` and redirect the standard out of the action to specified file. The value of the option should be a path-like object (`str`, `path`, etc), or `None`. The file will be opened in `append` mode so you will have to remove or truncate the file if the file already exists. If `stdout=False`, the output will be suppressed (redirect to `/dev/null` under linux)."
+    "Option `stdout` is applicable to script-executing actions such as `bash` and `R` and redirect the standard out of the action to specified file. The value of the option should be a path-like object (`str`, `path`, etc), or `False`. The file will be opened in `append` mode so you will have to remove or truncate the file if the file already exists. If `stdout=False`, the output will be suppressed (redirect to `/dev/null` under linux)."
    ]
   },
   {