doc: remove usage of you in n-api doc

We avoid using 'you' in the documentation based on our
guidelines. Remove usage in the n-api doc.

PR-URL: https://github.com/nodejs/node/pull/18528


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>