Added FAQ

FAQ.md

@@ -225,6 +225,7 @@ FairEmail follows all the best practices for an email client as decribed in [thi
 * [(129) Are ProtonMail, Tutanota supported?](#user-content-faq129)
 * [(130) What does message error ... mean?](#user-content-faq130)
 * [(131) Can you change the direction for swiping to previous/next message?](#user-content-faq131)
+* [(132) Why are new message notifications silent?](#user-content-faq132)
 
 [I have another question.](#user-content-support)
 
@@ -2222,6 +2223,14 @@ This behavior seems quite natural to me.
 
 <br />
 
+<a name="faq132"></a>
+**(132) Why are new message notifications silent?**
+
+Notifications appear to silent by default on some MIUI versions.
+Please see [here](http://en.miui.com/thread-3930694-1-1.html) how you can fix this.
+
+<br />
+
 ## Support
 
 If you have another question, want to request a feature or report a bug, you can use [this forum](https://forum.xda-developers.com/android/apps-games/source-email-t3824168).