Quickstart doc ambiguity: CHI namespaces

[rgeraskin]

In quickstart doc we see the Create Custom Namespace section:

It is a good practice to have all components run in dedicated namespaces. Let's run examples in the test namespace

But later in the Trivial example section, we install the ClickHouseInstallation manifest to the test-clickhouse-operator namespace. And it works only if we've installed the operator to the same namespace earlier: it's only one of three provided install solutions in this guide.

Moreover, it's not obvious from the doc that the operator watches for CHI only in the same namespace where it was installed by default.