docs(fix): Update README - clarify basic vs cluster install

[aimeeu]

clarify that in basic mode, you must install Spinnaker in the spinnaker-operator namespace

[armory-jenkins]

The title of this Pull Request needs to be changed to match the format:

<type>(<scope>): <subject>

See more details here: https://www.spinnaker.io/community/contributing/submitting/#commit-message-conventions

Some common examples are:

feat(armory.io): add docs.armory.io
fix(parser): grammar and spelling
style(loadingPage): made it super pretty!
refactor(helpMessages): changed order to make more sense

[coveralls]

Pull Request Test Coverage Report for Build 225552164

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 34.721%

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Totals
Change from base Build 214397227:	0.0%
Covered Lines:	1876
Relevant Lines:	5403

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💛 - Coveralls

[ncknt]

Typo OperAtor

[ncknt]

It would make more sense to me to use spinnaker as the namespace. That's the main thing the namespace contains.

[jasonmcintosh]

Note, we actually have MOST of our automation setup to use "spinnaker" as where spinnaker itself is deployed to and spinnaker-operator as where operator is deployed to. Should spinnaker operator be in "spinnaker" and there be a different standard for spinnaker itself?

[ncknt]

you must use the spinnaker-operator namespace

There's no technical reason for that. In basic mode, you can specify the namespace on the command line (kubectl create ns blah && kubectl -n blah apply -f deploy/operator/basic && kubectl -n blah apply -f deploy/spinnaker/basic/spinnakerservice.yml). In cluster mode, the namespace is also in the role binding, that's why we strongly suggest spinnaker-operator as a default.