Document VPA behavior for sidecar containers and how to change it

[omerap12]

What type of PR is this?

/kind documentation

What this PR does / why we need it:

Document VPA behavior for sidecar containers and how to change it

Which issue(s) this PR fixes:

Fixes #7641

Special notes for your reviewer:

Does this PR introduce a user-facing change?

NONE

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

NONE

[k8s-ci-robot]

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[adrianmoisey]

Does "Sidecar" refer to "A container that isn't the main one", or to the formal Sidecar definition (ie: https://kubernetes.io/docs/concepts/workloads/pods/sidecar-containers/)

I assume it's the former. It may be good to clarity this.

[omerap12]

Added in 3e4addd

[adrianmoisey]

Documentation is hard, so thanks for doing this.

I'm wondering how this page fits into the broader layout of the documents. My best guess is that it's a "FAQ" (ie: https://github.com/kubernetes/autoscaler/blob/master/vertical-pod-autoscaler/docs/faq.md).

I'm not entirely sold on that though. Having the document exist is a great first step, we can move it later if needed.

[omerap12]

Documentation is hard, so thanks for doing this.

I'm wondering how this page fits into the broader layout of the documents. My best guess is that it's a "FAQ" (ie: https://github.com/kubernetes/autoscaler/blob/master/vertical-pod-autoscaler/docs/faq.md).

I'm not entirely sold on that though. Having the document exist is a great first step, we can move it later if needed.

I was wondering about that as well. Perhaps @voelzmo might have some ideas on how the overall layout should be structured

[omerap12]

/retest