add useDetailedSubHeadings to syncable settings (#153)

Author: jmawet

backend/Models/MoonfinSettingsProfile.cs

@@ -105,6 +105,9 @@ public class MoonfinSettingsProfile
     [JsonPropertyName("enableFolderView")]
     public bool? EnableFolderView { get; set; }
 
+    [JsonPropertyName("useDetailedSubHeadings")]
+    public bool? useDetailedSubHeadings { get; set; }
+
     [JsonPropertyName("confirmExit")]
     public bool? ConfirmExit { get; set; }