Review Docu - some minor findings

[Jeansen]

https://knative.dev/docs/install/operator/knative-with-operators/#install-the-knative-operator is a bit outdated.

Findings:

• Table at the top references operator version 1.13, current version is 1.14.x
• Chapter: Verify your Knative Operator installation: kubectl apply -f https://github.com/knative/operator/releases/download/knative-v1.14.1/operator.yaml does not install to default namespace but to knative-operator.

Operator installation says, one should use kubectl apply -f https://github.com/knative/operator/releases/download/knative-v1.14.1/operator.yaml.

Why not reference OLM https://artifacthub.io/packages/olm/community-operators/knative-operator? I could not find any information regarding the OLM in the docs...

[houshengbo]

@Jeansen Thank you so much. I just changed the default ns, need to change the doc as well.