Add documentation around the Altinity operator

[bmtcril]

We're running into a few places where we need specific configuration options in the Altinity operator to make it behave the way things do in Altinity Cloud / CH Cloud. See here for more info:

openedx/tutor-contrib-aspects#767

[bmtcril]

@Ian2012 are there more things we should document about the operator, or is the work to integrate that still ongoing?

[Ian2012]

Worth adding:

• Hardware requirements
• k8s Taints
• k8s clickhouse workers
• user/function replication

Everything else will be out of scope cause will be specific for every installation, requirement, and infrastructure provider

[Ian2012]

Adding a link to the future documentation on Harmony with ClickHouseOperator should be enough