📝Add missing main.py in tutorial on CLI option names (#868)

Co-authored-by: svlandeg <svlandeg@github.com>

docs/tutorial/options/name.md

@@ -81,7 +81,7 @@ Options:
   --help                Show this message and exit.
 
 // Try it
-$ python --name Camila
+$ python main.py --name Camila
 
 Hello Camila
 ```