added instructions to run setup.py to contributing.rst
added instructions to run setup.py to contributing.rst

pydanny/django-admin2,andrewsmedina/django-admin2,pydanny/django-admin2,yarbelk/django-admin2,hnakamur/django-admin2,yarbelk/django-admin2,hnakamur/django-admin2,andrewsmedina/django-admin2,andrewsmedina/django-admin2