Update documentation as test is expecting Boolean

[vaibhavsahni009]

https://github.com/100xdevs-cohort-2/assignments/blame/2f0644e7f096180fb55641d233098527daebf453/week-3/02-jwt/index.js#L36

Update response as the test expects Boolean (true) once the decode is successful rather than the payload object.

Up for discussion, if we need to update the test to expect the payload.