allow at least one level of nesting

[jowenn]

Quick and dirty fix for issue https://github.com/encode/django-rest-framework/issues/5324

Of course a more general solution would be better, but at least this is able to handle one level of nested urls

[carltongibson]

@jowenn Thanks for the input. We need to do something along this line. (But we also need to make sure think through related issues, such as styling and documentation, and no doubt others.)

I'll leave this open as is for now and review fully w/b 14th.

Ref #5077

[carltongibson]

Thanks for input here. We've gone with #5334 in the end.

[jowenn]

Great, looking forward to see it hit pypi

[carltongibson]

@jowenn See #5340 🙂