doc: fix nits in http(s) server.headersTimeout

* Fix sort orders of sections and bottom references.
* Fix links.
* Unify spelling.
* Add missing YAML block.

PR-URL: https://github.com/nodejs/node/pull/24697


Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>