Update README.md

fixed missing .py extension in scripts list usage instructions.

scripts/README.md

@@ -4,5 +4,5 @@ This folder contains one-off scripts for working with ATT&CK content. These scri
 
 | script | description |
 |:-------|:------------|
-| [techniques_from_data_src.py](techniques_from_data_src.py) | Fetches the current ATT&CK STIX 2.0 objects from the ATT&CK TAXII server, prints all of the data sources listed in Enterprise ATT&CK, and then lists all the Enterprise techniques containing a given data source. Run `python3 techniques_from_data_source -h` for usage instructions. |
+| [techniques_from_data_src.py](techniques_from_data_src.py) | Fetches the current ATT&CK STIX 2.0 objects from the ATT&CK TAXII server, prints all of the data sources listed in Enterprise ATT&CK, and then lists all the Enterprise techniques containing a given data source. Run `python3 techniques_from_data_source.py -h` for usage instructions. |
 | [techniques_data_sources_vis.py](techniques_data_sources_vis.py) | Generate the csv data used to create the "Techniques Mapped to Data Sources" visualization in the ATT&CK roadmap. Run `python3 techniques_data_sources_vis.py -h` for usage instructions. |