[8.15] Update warning on `xpack.fleet.enableExperimental` (#…

…188917) (#188983)

# Backport

This will backport the following commits from `main` to `8.15`:
- [Update warning on `xpack.fleet.enableExperimental`
(#188917)](#188917)

<!--- Backport version: 9.4.3 -->

### Questions ?
Please refer to the [Backport tool
documentation](https://github.com/sqren/backport)

<!--BACKPORT [{"author":{"name":"Luca
Belluccini","email":"[email protected]"},"sourceCommit":{"committedDate":"2024-07-23T16:25:34Z","message":"Update
warning on `xpack.fleet.enableExperimental` (#188917)\n\n##
Summary\r\n\r\nAdd warning on `xpack.fleet.enableExperimental`
settings.\r\n\r\n### For maintainers\r\n\r\n- [x] Review the
wording.\r\n- [ ] Backport to all
versions","sha":"647b22266eea9858f682894393ab8d64fe7f6160","branchLabelMapping":{"^v8.16.0$":"main","^v(\\d+).(\\d+).\\d+$":"$1.$2"}},"sourcePullRequest":{"labels":["release_note:skip","backport:all-open","v8.16.0"],"title":"Update
warning on
`xpack.fleet.enableExperimental`","number":188917,"url":"https://github.com/elastic/kibana/pull/188917","mergeCommit":{"message":"Update
warning on `xpack.fleet.enableExperimental` (#188917)\n\n##
Summary\r\n\r\nAdd warning on `xpack.fleet.enableExperimental`
settings.\r\n\r\n### For maintainers\r\n\r\n- [x] Review the
wording.\r\n- [ ] Backport to all
versions","sha":"647b22266eea9858f682894393ab8d64fe7f6160"}},"sourceBranch":"main","suggestedTargetBranches":[],"targetPullRequestStates":[{"branch":"main","label":"v8.16.0","branchLabelMappingKey":"^v8.16.0$","isSourceBranch":true,"state":"MERGED","url":"https://github.com/elastic/kibana/pull/188917","number":188917,"mergeCommit":{"message":"Update
warning on `xpack.fleet.enableExperimental` (#188917)\n\n##
Summary\r\n\r\nAdd warning on `xpack.fleet.enableExperimental`
settings.\r\n\r\n### For maintainers\r\n\r\n- [x] Review the
wording.\r\n- [ ] Backport to all
versions","sha":"647b22266eea9858f682894393ab8d64fe7f6160"}}]}]
BACKPORT-->

Co-authored-by: Luca Belluccini <[email protected]>

docs/settings/fleet-settings.asciidoc

@@ -311,4 +311,10 @@ List of proxies to access {fleet-server} that are configured when the {fleet} ap
 `xpack.fleet.enableExperimental`::
 List of experimental feature flag to enable in Fleet.
 
+[NOTE]
+====
+Experimental features should not be enabled in production environments.
+The features in this section are experimental and may be changed or removed completely in future releases.
+Elastic will make a best effort to fix any issues, but experimental features are not supported to the same level as generally available (GA) features.
+====