Docs tweak with a typo fix and a clarification on how the two available
settings interact (essentially
https://github.com/elastic/elasticsearch/issues/27871). I'm also open to
including this info in the more generic settings API but feels like a
simple enough callout to add to the security API.
**Problem:**
For historical reasons, source files for the Elasticsearch Guide's security, watcher, and Logstash API docs are housed in the `x-pack/docs` directory. This can confuse new contributors who expect Elasticsearch Guide docs to be located in `docs/reference`.
**Solution:**
- Move the security, watcher, and Logstash API doc source files to the `docs/reference` directory
- Update doc snippet tests to use security
Rel: https://github.com/elastic/platform-docs-team/issues/208