add reference to beta

Author: bailey

content/account-and-profile/setting-up-and-managing-your-github-profile/customizing-your-profile/personalizing-your-profile.md

@@ -153,6 +153,8 @@ Achievements celebrate specific events and actions that happen on GitHub. They w
 
 To stop private contributions from counting toward your Achievements or to turn off Achievements entirely, see "[Showing your private contributions and Achievements on your profile](/articles/publicizing-or-hiding-your-private-contributions-on-your-profile)."
 
+Note: This feature is currently in beta and subject to change.
+
 {% endif %}
 
 ## List of qualifying repositories for Mars 2020 Helicopter Contributor achievement