aws-eks-v2: Architecture Diagram Broken

### Describe the issue

Was looking at implementing docs for the Ruby language bindings and noticed the architecture diagram is a little broken.

cmark renders it in the least broken way (Github's native)

redcarpet renders differently, however, this was after mangling the input, without the mangling the text fence broke the rest of the documentation

Realistically, this should have a documentation fix:

Note that the text fence is on the same line as the top of the box and this is why it is breaking

### Links

https://github.com/aws/aws-cdk/tree/main/packages/aws-cdk-lib/aws-eks-v2
https://rubygems.omarqureshi.net/docs/AWSCDK/EKSv2/index.html

Start in packages/aws-cdk-lib/aws-eks-v2 and inspect the documentation source for the architecture diagram, paying attention to the text fence at the top of the box. Compare the rendered result with the linked Ruby AWSCDK/EKSv2 documentation; done means the diagram and the surrounding documentation render correctly without input mangling.

Written by the indexing model from the issue text.