add more guided access detail

Author: friadev

docs/os/ios-overview.md

@@ -260,6 +260,8 @@ Sometimes you might want to hand your phone to someone to make a call or do a sp
 
 Guided Access isn't foolproof, it's possible you could leak data you don't intend to or it could be bypassed.
 
+You should only use Guided Access for situations where you casually hand your phone to someone to use, not to protect against advanced adversaries.
+
 </div>
 
 ### Redacting Elements in Images