chore(contributors): Avoid Map<S, O> usage (#2024)
chore(contributors): Avoid Map<S, O> usage (#2024)

* chore(contributors): Avoid Map<S, O> usage

I'm writing an errorprone check for `Map<String, Object>` usage, and I want a place that I can link to from the custom check.

* Update back-end-code.md
spinnaker/spinnaker.github.io,spinnaker/spinnaker.github.io,spinnaker/spinnaker.github.io