Updating onboarding issue structure to be clearer

Why is this change being made?

I believe it can be a bit confusing to say that is from the onboarding issue is structured with tasks from Day 1 to Day 5-30 so I thought we could change so highlight that it's divided in days until day 5 and then from week 2 to 4.

@Mowry @ashjameson @alex_venter @brufener would love your input. Ashley, I assigned to you as I raised this in our call earlier today.

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