Update support onboarding module order and completion to be more flexible
As per gitlab-com/support/support-team-meta#4470 (closed) , it's clear that the order of the onboarding modules and the timing of when each one is opened/closed really depends on the individual and their discussions with their manager/onboarding buddy.
This MR updates the language to put what we do in practice "on paper", and allows an individual more flexibility in discussion with their manager on how and when to complete the specific onboarding modules.
Edited by Cynthia "Arty" Ng