Add flac/mp3 (for large coverart)

Author: onesounds

Flow.Launcher/ViewModel/ResultViewModel.cs

@@ -182,6 +182,8 @@ public ImageSource PreviewImage
             or ".bmp"
             or ".gif"
             or ".wmv"
+            or ".mp3"
+            or ".flac"
             or ".mp4";
 
         public GlyphInfo Glyph { get; set; }