For me, this is what I’d expect:
- hosting: about choosing and managing the host (server)
- Installation: getting to « discourse exists and I can log in as admin and do stuff »
- configuration: all the nitty-gritty regarding the various settings
I think that for somebody starting out, the distinction between core and « plugin bundled in » is not very obvious. So I’d include those in configuration— or at least very clear pointers.