🌱 Update Proxmox quick-start docs

[mcbenjemaa]

What this PR does / why we need it:

This PR updates the quickstart docs for Proxmox Provider:

• Remove the addition of IPAM provider in-cluster into clusterctl config as the IPAM provider got included in clusterctl.
• Add new note regarding the Proxmox credentials

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

/area documentation
/cherry-pick release-1.7

[k8s-ci-robot]

@mcbenjemaa: The label(s) area/book cannot be applied, because the repository doesn't have them.

In response to this:

What this PR does / why we need it:

This PR updates the quickstart docs for Proxmox Provider:

• Remove the addition of IPAM provider in-cluster into clusterctl config as the IPAM provider got included in clusterctl.
• Add new note regarding the Proxmox credentials

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #

/area book
/cherry-pick release1.7

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[mcbenjemaa]

/area documentation

[mcbenjemaa]

/cherry-pick release-1.7

[k8s-infra-cherrypick-robot]

@mcbenjemaa: once the present PR merges, I will cherry-pick it on top of release-1.7 in a new PR and assign it to you.

In response to this:

/cherry-pick release-1.7

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[chrischdi]

/lgtm

[chrischdi]

small wording nit

/lgtm cancel

[chrischdi]

/lgtm

[k8s-ci-robot]

LGTM label has been added.

Git tree hash: 9210563fcc7b11e9e328800e24f0de26611b6b0a

[sbueringer]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: sbueringer

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [sbueringer]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[k8s-infra-cherrypick-robot]

@mcbenjemaa: new pull request created: #10779

In response to this:

/cherry-pick release-1.7

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.