Update dumpscript docs
Update dumpscript docs

* fixes
https://github.com/django-extensions/django-extensions/issues/929
*

linuxmaniac/django-extensions,haakenlid/django-extensions,linuxmaniac/django-extensions,django-extensions/django-extensions,haakenlid/django-extensions,django-extensions/django-extensions,linuxmaniac/django-extensions,django-extensions/django-extensions,haakenlid/django-extensions