[docs] Properly reflect diversity in Swift programmers in emoji.

Author: varungandhi-apple

docs/HowToGuides/FirstPullRequest.md

@@ -6,7 +6,7 @@ you are an experienced open source contributor who is excited about Swift, or
 maybe you are somewhere in-between. Regardless of your background, we are
 excited to have you contribute and improve the developer experience for Swift
 programmers all over the globe.
-:sparkles::child::student::woman_technologist::technologist::man_technologist::sparkles:
+:sparkles:🧒🏾🧑🏼‍🎓👩🏽‍💻🧑🏻‍💻👨🏿‍💻:sparkles:
 
 This document provides a high-level overview of different parts of the
 contribution process.