Since `cabal init` is no longer interactive by default
(as per my version, 3.0.0.0), including other minor
changes to the `init` process, change the `cabal init`
section to mention the usage of the `--interactive` flag,
and the new minor changes (which/the order questions
are asked, what the terminal output is).

I came across this problem while learning `cabal`
(having recently migrated from `stack`) and reading
this section of Cabal's quickstart guide.

To be proactive, add TIP relatively-linking to the
new getting started guide
(https://cabal.readthedocs.io/en/latest/getting-started.html)
in a TIP at the top of the page.  Implemented
because that is the best "entrypoint" to the docs,
but many resources/searches still point the user
to this page being modified.