docs: update local and refresh providers guide

[MuhammadM1998]

Resolves #606.

This updates the local & refresh providers docs to indicate that we can pass any payload to the signIn method, not just a user & password. I've also added an example and reworded some parts that I felt was not clear enough. Feel free to reedit if needed 🙏

[zoey-kaiser]

Hi @MuhammadM1998 👋

Thanks for updating the docs so thoroughly! I am doing a release at the moment, which is why I quickly wanted to chim in here. I will look at these docs in the coming days. As your docs can update, whichout doing a release, ill prio this after the PRs with code changes!

[MuhammadM1998]

Nice to know thanks! Waiting for the release and the new session pointer 👀

[zoey-kaiser]

Hi @MuhammadM1998 👋

Please resolve the merge conflicts and then we can merge this! AFAIK This will also fix an issue in our changes:

The backend response returns an object named token not a single value. See the references to this here: #649

[MuhammadM1998]

@zoey-kaiser The conflict is fixed now. Feel free to quickly rereview

[zoey-kaiser]

One minor nit 😄

[zoey-kaiser]

Amazing! Thank you so much for the changes. I think you really improved the docs for the refresh provider. I apologize for it taking longer to merge this PR, the start of the year was pretty crazy!