email otp type - deprecated comment

[landsman]

What kind of change does this PR introduce?

just link to documentation and flag two options as deprecated

What is the current behavior?

• https://github.com/supabase/gotrue/issues/905#issuecomment-1533128779
• https://github.com/supabase/supabase/issues/18680

What is the new behavior?

Tell developer in his IDE about deprecated values and save a lot of time

Additional context

Let's make this as standard please. Documentation in the code is the best.