Simplify config and getting started guide, with examples of optimal setups

[noahnu]

The config can be confusing, even with the documentation. Ideally 99% of users should be able to just run:

yarn monodeploy

we should revisit the defaults, and tweak them (it'd be a breaking change). We could also look at offering an interactive yarn monodeploy init subcommand leveraging https://github.com/enquirer/enquirer.

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Something that might help simplify the config would be to leverage subcommands with clipanion more. So:

yarn monodeploy plan
yarn monodeploy build
yarn monodeploy publish

while still having an option which does all 3 (yarn monodeploy? or when you run build perhaps it updates the changeset file with build status so it can be skipped if nothing has changed?)