fix (docs): fix documentation about useAuthState composable

[anjarupnik]

Contributes to fixing documentation about useAuthState in Session access and management. In the example for useAuthState composable useAuth was used. And instead of setToken, getToken was defined as one of the functions.

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• issue number linked above after pound (#)
  • replace "Closes " with "" or other if this PR does not close the issue
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[zoey-kaiser]

Fixed in #569. Sorry that I cannot merge your PR. I am currently migrating the docs and fixing the merge conflicts would have been a bigger headache then me just quickly adding it to another PR! Thanks for the catch 💪