Improve documentation section that covers "Project setup"

[stichbury]

Child of #2799 This is a parent itself and will cover all the changes necessary to popular pages in the "Project setup" section. Won't be addressed until 0.19.0 and is relatively low priority compared to #3200

[astrojuanlu]

That section definitely could use some love but without specific things to do or a timeframe this ticket will likely linger forever. I'm closing for now, we can open at a later time.