docs: redirect from custom sign in page if signed in (#6589)
* Add success handler to getServerSideProps
This change adds a code that gives the user a sense of direction on what to do if the OAuth sign in is successful.
* Update docs/docs/configuration/pages.md
This is noted
Co-authored-by: Balázs Orbán <info@balazsorban.com>
* Update getSession to getServerSession
Change the getSession in getServerSideProps to the new getServerSession
* Apply suggestions from code review
* Apply suggestions from code review
* Apply suggestions from code review
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Co-authored-by: Balázs Orbán <info@balazsorban.com>
