[ES|QL] Better support for links in generated docs

[not-napoleon]

Description

Follow up from #113263

We want to be able to include links in our generated docs, without leaking asciidoc into responses that aren't then rendered. We have two proposals for how to best do this:

1 - Strip asciidoc links from all generated files except the actual docs. There's already logic in the generation code that does this for the json files.

2 - Build a map of keywords to links and scan the generated docs for those keywords to replace with the links.

This issue is the correct place to discuss those two options, or suggest other possibilities. Note also that we currently leak markdown links at places as well.

[elasticsearchmachine]

Pinging @elastic/es-docs (Team:Docs)

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)