doc: fix markdown syntax and HTML tag misses

PR-URL: https://github.com/nodejs/node/pull/40608


Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Richard Lau <rlau@redhat.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Voltrex <mohammadkeyvanzade94@gmail.com>