doc: eliminate _you_ from N-API doc

The STYLE_GUIDE indicates that personal pronouns like "you" should be
avoided in reference documentation. Remove "you" from N-API doc.

PR-URL: https://github.com/nodejs/node/pull/21382


Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>