doc: Update FVT prerequisites

[ckadner]

Motivation

After many attempts to run the FVT tests it became clear that an undersized Kubernetes cluster (insufficient resources) prevented the FVTs to succeed.

Modifications

Update the FVT README with a Prerequisite section that outlines the required CLIs and the minimum cluster size.

Result

The FVT tests completed successfully.

/cc @njhill @chinhuang007

[kserve-oss-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: ckadner
To complete the pull request process, please assign animeshsingh after the PR has been reviewed.
You can assign the PR to them by writing /assign @animeshsingh in a comment when ready.

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

Needs approval from an approver in each of these files:

• OWNERS

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

[njhill]

@ckadner there's a linter failure, you need to run make fmt which will fail the first time but make the required formatting changes. So running a second time should pass and you can then commit those changes.

[ckadner]

@ckadner there's a linter failure, you need to run make fmt which will fail the first time but make the required formatting changes. So running a second time should pass and you can then commit those changes.

Thanks @njhill -- I am too used to my IDE doing the code cleanup for me

[njhill]

/lgtm

[ckadner]

Thanks Nick!