default-system-deployment-versions.md - Update system cluster versions

[rseldner]

Updated to include default system deployments for ECE versions

• 4.0.0
• 3.8.0
• 3.7.3
• 3.7.2

[georgewallace]

LGTM

[georgewallace]

@rseldner Should the updates for 3.8.0, 3.7.3, 3.7.2 be made to the old docs as well? https://www.elastic.co/guide/en/cloud-enterprise/3.8/ece-system-deployment-versions.html

[rseldner]

@rseldner Should the updates for 3.8.0, 3.7.3, 3.7.2 be made to the old docs as well? https://www.elastic.co/guide/en/cloud-enterprise/3.8/ece-system-deployment-versions.html

Yes, though I was not sure whether there was a simple way to backport or if separate manual PRs were needed for 3.8 and 3.7

[georgewallace]

@rseldner manual PRs are needed unfortunately as they are in asciidoc and the information changes between the versions.

[rseldner]

@rseldner manual PRs are needed unfortunately as they are in asciidoc and the information changes between the versions.

Makes sense. I figured I'd start from the latest.
I can submit two follow-up asciidoc PRs shortly.

[rseldner]

@georgewallace 3.7 and 3.8 PRs submitted and linked above