feat: update password strength requirements (#20251)

Update passwords.mdx

apps/docs/pages/guides/auth/passwords.mdx

@@ -150,6 +150,10 @@ Supabase Auth uses [bcrypt](https://en.wikipedia.org/wiki/Bcrypt), a strong pass
 
 The hash is stored in the `encrypted_password` column of the `auth.users` table. The column's name is a misnomer (cryptographic hashing is not encryption), but is kept for backward compatibility.
 
+### How will strengthened password requirements affect current users?
+
+Existing users can still sign in with their current password even if it doesn't meet the new, strengthened password requirements. However, if their password falls short of these updated standards, they will encounter a `WeakPasswordError` during the `signInWithPassword` process, explaining why it's considered weak. This change is also applicable to new users and existing users changing their passwords, ensuring everyone adheres to the enhanced security standards.
+
 export const Page = ({ children }) => <Layout meta={meta} children={children} />
 
 export default Page