doc: remove superfluous adverb from style guide

PR-URL: #19246
Reviewed-By: Daijiro Wachi <daijiro.wachi@gmail.com>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Gibson Fahnestock <gibfahn@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/STYLE_GUIDE.md

@@ -13,8 +13,7 @@
 * American English spelling is preferred. "Capitalize" vs. "Capitalise",
   "color" vs. "colour", etc.
 * Use [serial commas][].
-* Generally avoid personal pronouns in reference documentation ("I", "you",
-  "we").
+* Avoid personal pronouns in reference documentation ("I", "you", "we").
   * Pronouns are acceptable in more colloquial documentation, like guides.
   * Use gender-neutral pronouns and mass nouns. Non-comprehensive
     examples: