doc: replace uses of `you` and other style nits

Replace uses of the pronouns `you` and `your` throughout
the docs + other minor style nits

PR-URL: https://github.com/nodejs/node/pull/12673


Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>