[overlay] collect few examples of kustomize vs ytt overlay to be included in docs

[cppforlife]

comparison comes up pretty often so it would be nice to document some common comparisons.

[cppforlife]

• shared config between Job and CronJob: https://kubernetes.slack.com/archives/CH8KCCKA5/p1566924247453400

[lukasmrtvy]

AFAIK:

ytt:

• terraform provider
• better templating ( usually infrastructure secrets referenced in terraform for boostraping )

kustomize:

• better support for cloud native well-known toolset ( flux, argo, etc ), it does not need to be direct integration, but examples..
• kustomize integration in kubectl ( old version, but still )
• no official terraform provider ( no templating without leaking secrets in tf diffs )

Did You consider to distribute ytt as krew plugin ?

[cppforlife]

better support for cloud native well-known toolset ( flux, argo, etc ), it does not need to be direct integration, but examples..

that's worth mentioning in docs on how to integrate with argo, and others.

Did You consider to distribute ytt as krew plugin ?

not really. what do you think will be main advantage vs just using ytt binary directly?