doc: fix nits in net.md

* Add missing types.
* Fix function signatures.
* Fix typos.
* Unify comment style.
* Fix ASCII sorting of bottom references.

PR-URL: https://github.com/nodejs/node/pull/29577


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Anto Aravinth <anto.aravinth.cse@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>