Fixes #983

Dependencies installed via setup.py stay in their eggs and their
templates won't be found by Django. This caused a
TemplateNotFoundError when users were trying to use
Django's admin to set categories.
Using the admin is unsupported, but this still prevents a similar error
from happening when we use other dependencies that ship templates. It
also shouldn't slow down production use.

Fixes #761

To set a base for upcoming docs changes, the docs directory structure
has been streamlined to follow a simplified version of Django's docs.

The old _draft folder has been removed. Both files from there and the
current docs that don't fit nicely into the new structure are in _old/
for the moment.

Simplest way is to override templates rather.

Related to #422

Was using wrong setting.