Found a typo. "Kubernetes" is misspelled halfway the sentence:

The Pulumi Kubernetes Operator is an extension pattern that enables Kuberentes users to create a

Stack

as a first-class API resource, and use the

StackController

to drive the updates of the Stack until success.

https://www.pulumi.com/docs/guides/continuous-delivery/pulumi-kubernetes-operator/#overview

thanks @limited-rainbow-51650 will send a PR now to fix this