Update docs according to #215

[illia-v]

No description provided.

[coveralls]

Coverage remained the same at 100.0% when pulling ae2dad8 on illia-v:more-allowed-data-structures-docs into 03d76f5 on vimalloc:master.

[vimalloc]

I'm not actually sure I want to update this. I think ('headers',) could be a lot more confusing then ['headers'] for people who are not as familiar with python, and tuples or lists should work fine for this setting. Thoughts?

[illia-v]

Agree, but JWT_TOKEN_LOCATION does default to ('headers',).
We can change it to default to just a string and then change the docs. Will it be good?

[vimalloc]

It does default to ('headers',), but functionally if it defaults to that or ['headers'] doesn't have any real affect for users, and the later is (imo) generally better understood. I don't really want to change it to just headers either, as having it displayed as a list/sequence/etc in the documentation makes it easier to see at a glance that you can have multiple token locations instead of just one, without having to read the fine print as it were.

These are my thoughts on the matter, but I would love to hear what you think about that. 👍

[vimalloc]

Should also note I do want to update the documentation to say that you can use a sequence, set, etc instead of just a list for these fields. I think there is absolutely value in that 👍

[illia-v]

No problem in changing it to list :)

[vimalloc]

Right on. Thanks again for contributing! 👍