Update README.md

Author: mr-c

README.md

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 A collection of scripts to demonstrate the use of the [new Python classes for loading and parsing CWL v1.0 documents](https://github.com/common-workflow-language/cwl-utils/blob/master/cwl_utils/parser_v1_0.py).
 
+
+`cwl_utils/parser_v1_0.py` was created via
+`schema-salad-tool --codegen python https://github.com/common-workflow-language/common-workflow-language/raw/master/v1.0/CommonWorkflowLanguage.yml`
+
 Requires Python 3.6.x or Python 3.7
 
 ``` bash