doc: add more missing backticks

Also, fix some other nits in passing
(formatting, punctuation, typos, redundancy, obsoleteness).

PR-URL: https://github.com/nodejs/node/pull/20438


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>