docs(faq): note default behavior for account linking

[ThangHuuVu]

☕️ Reasoning

Explain default behavior for account linking in FAQ.

🧢 Checklist

• [x] Documentation
• [x] Ready to be merged

🎫 Affected issues

#3300

📌 Resources

• Contributing guidelines
• Code of conduct
• Contributing to Open Source

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Name	Status	Preview	Updated
next-auth	✅ Ready (Inspect)	Visit Preview	Aug 13, 2022 at 7:58AM (UTC)

[martin-fv]

It would be nice if there is a page for info about how to disable account linking or a code snippet to only allow account linking with the same email.