Enhance docs around kube-mgmt cache customization

[phenixblue]

What would you like to be added:

Need to addd some verbiage to the docs that cover thee possibility of adjusting resources (CPU/MEM) as you add additional Kubernetes resources to be replicated by kube-mgmt.

Why is this needed:

I've noticed on some large clusters with many objects that the HPA kicks in automatically following an initial deployment of MagTape and remains at max replicas. This seems to be associated with kube-mgmt replication (ie. more resource types/number of a given type of resource on the cluster).

Possibly look into adjusting sync interval or adjusting resource location for the kube-mgmt container. At the very least we need to call it out in the dos.