* Remove `es-test-dir` book-scoped variable
* Remove `plugins-examples-dir` book-scoped variable
* Remove `:dependencies-dir:` and `:xes-repo-dir:` book-scoped variables
- In `index.asciidoc`, two variables (`:dependencies-dir:` and `:xes-repo-dir:`) were removed.
- In `sql/index.asciidoc`, the `:sql-tests:` path was updated to fuller path
- In `esql/index.asciidoc`, the `:esql-tests:` path was updated idem
* Replace `es-repo-dir` with `es-ref-dir`
* Move `:include-xpack: true` to few files that use it, remove from index.asciidoc
**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
Co-Authored-By: Przemysław Witek <przemyslaw.witek@elastic.co>
Co-Authored-By: David Roberts <dave.roberts@elastic.co>
Co-Authored-By: Ed Savage <32410745+edsavage@users.noreply.github.com>
