Documentation includes mention of deleted token salting

[dgerlanc]

The documentation includes a setting for SALT_LENGTH even though salting was removed long ago.

Would be great to remove this reference as it suggests that salting of tokens is still used!

I searched the head of the develop branch and could not find a mention of this setting except in the changelog and migrations so I'm not sure why it's showing up in the docs!

See https://jazzband.github.io/django-rest-knox/settings/.

[johnraz]

This most likely comes from the fact that the gh-pages branch is outdated ... https://github.com/jazzband/django-rest-knox/blob/gh-pages/settings/index.html.

I will mention this in #304

[giovannicimolin]

@johnraz @dgerlanc We now have a Ci job that automatically deploys the latest documentation to GH-pages.

#343

[johnraz]

@giovannicimolin wonderful doc is up to date now! Closing this one