Bug: Documentation hyperlinks use indexes instead of strings

[x-N0]

Documentation's hyperlinks use indexes instead of strings

https://django-sms.readthedocs.io/en/latest/#id12 Brings you to the Console Backend section.

But going into the docs and clicking the Console Backend item yields the following url https://django-sms.readthedocs.io/en/latest/#console-backend, which doesn't work because the right url is using IDs.

Also the fork me logo is broken due to public access denied
https://s3.amazonaws.com/github/ribbons/forkme_right_darkblue_121621.png

Good first issue for a newbie IMO
Thanks for the library!!