Documented issues with local station fallbacks.

docs/engine-features.md

@@ -38,6 +38,14 @@ transition play-out to a Fallback Playlist (see Auto Pilot).
 In case there is no schedule delivered by Steering, engine provides multiple
 fallback handling scenarios. The available fallbacks are evaluated in following order:
 
-1. **Timeslot Fallback**: //TODO explain
-2. **Show Fallback**: //TODO explain
-3. **Station Fallback**: //TODO explain
+1. **Timeslot Fallback**:
+
+2. **Show Fallback**:
+
+3. **Station Fallback**:
+
+3.1 Station Fallback via remote playlist
+
+3.2 Station Fallback via local music folder
+
+Note: All filenames in the music folder should be ASCII encoded, otherwise this may cause engine failures.