auto-generated files should be separate from source

I keep stumbling on the fact that parts of the mdx files I should edit inline, while others are auto-generated from other snippets, and I actually need to edit somewhere else. It needs to be much clearer where I should edit things. We should have src/.. files where I make changes, and target/.. ones that are the result of any script that merges them, or codegens, or whatever.

For example, in kubernetes-deployment.mdx, there are things that are injected from various other imports. But then there's also text where the source is actually this file. This makes it extremely confusing to find where to make changes. CI does at least yell at me when I get it wrong, but this makes all doc editing way more painful than it should be.