Added known problems

FAQ.md

@@ -31,6 +31,13 @@ For:
 Anything on this list is in random order and *might* be added in the near future.
 
 
+## Known problems
+
+* Large replied/forwarded texts resulting in [ANR](https://developer.android.com/topic/performance/vitals/anr)s
+* Occasional redrawing of conversation thread on new/updated messages
+* Message text sometimes hidden under *Show original*
+
+
 ## Frequently requested features
 
 * Previewing message text in notifications: this is not possible because the message text is initially not downloaded.

README.md

@@ -87,6 +87,8 @@ FairEmail requires at least Android 6 Marshmallow.
 
 FairEmail will work properly on devices without any Google service installed.
 
+See [here](https://github.com/M66B/open-source-email/blob/master/FAQ.md#known-problems) for known problems.
+
 ## Support / frequently asked questions
 
 See [here](https://github.com/M66B/open-source-email/blob/master/FAQ.md) for a list of often asked questions and about how to get support.