[Feature] add autoModeConfig to schema

[aaronzshey]

What feature/behavior/change do you want?

On the eksctl config file schema website, the autoModeConfig field is missing.

Why do you want this feature?

The autoModeConfig field is used far and wide, such as on the AWS quickstart guide. It would be helpful for it to be on the config schema site as well.

[github-actions]

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