Fix error when invoking manage.py with no arguments

[wookie184]

Previously when running python manage.py:

Traceback (most recent call last):
  File "C:\Users\wookie184\Documents\GitHub\site\manage.py", line 217, in <module>
    main()
  File "C:\Users\wookie184\Documents\GitHub\site\manage.py", line 198, in main
    _static_build = "distill" in sys.argv[1]
IndexError: list index out of range

Now displays the help command instead

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[coveralls]

Coverage remained the same at 100.0% when pulling 42a8e91 on fix-manage-py-no-args into 0e6b708 on main.

[shtlrs]

Thanks ! :D