Adding Net Promoter Score to the Vercel form

[prajectory]

An NPS score needs to be calculated so that we can track our performance on the form. For this, a question has been drafted at this link.

This question must appear as the last question on the form after submission.

[nathanbaleeta]

I believe this metric should be catered for in the new webApp soon to be launched as the current vercel submissions form will be archived late 2022. Thanks.

Cc: @prajectory