Update README.md with Confirm signup info

[akdeb]

This should enable Confirm signup to work for new users

Proposed README changes:

For signup:

To make sure sign up works through the supabase "Confirm signup" tab. Add "/auth/callback" after {{ .ConfirmationURL }} like href="{{ .ConfirmationURL }}/auth/callback" so the project catches the sign up route in the right callback.

[vercel]

@akdeb is attempting to deploy a commit to the Leap AI Team on Vercel.

A member of the Team first needs to authorize it.

[akdeb]

This is a temp fix until this issue is fixed https://github.com/supabase/auth-helpers/issues/716#issue-2066349576
Ideally when emailRedirectTo is working correctly, we want to set this to

emailRedirectTo: `${requestUrl.origin}/auth/callback/`

[agnelnieves]

Hey, is this still an issue? I am having the same issue where i get the 401: invalid claim: missing sub claim error