Create LP-Cumulus-Access-Constraints-Procedure (#3984)

[etcart]

Summary: document SOP for updating access constraints from LP

Addresses CUMULUS-XX: Develop amazing new feature

Changes

• Detailed list or prose of changes
• ...

PR Checklist

• Update CHANGELOG
• Unit tests
• Ad-hoc testing - Deploy changes and test manually
• Integration tests

[etcart]

I merged this pointing at my cumulus core branch so that CICD can be run, but I realized I needed to reach back for some comments(sorry I got ahead of myself).
those comments are: can we generalize this to non-LP specific usages as much as possible?
there are several places where I think a non-LP user is going to be confused by this as an SOP, one example of this in the docs file

[etcart]

I think this elpdvx3 is something specific to your stack/environment? can you describe this such that someone can find their version of the same? I'm assuming it's an EC2 instance by context clues, is this one of your stack's ECS instances?