feat: add link to comic-book about OAuth2 to docs

[achedeuzot]

This was merged in #1019 but was later removed when merging #863

This PR re-adds the change in #1019. It's still strange why it was removed, but some changed might have been accidentally removed on other occasions.

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[aeneasr]

Hello, after a review we decided not to include the linked blog post in our documentation because we felt it does not add additional value to our documentation. Thank you though for your contribution!

[achedeuzot]

Oh okay. Too bad.