Add way to set flags for Electron before the app starts

ElectronNET.API/App.cs

@@ -539,9 +539,9 @@ namespace ElectronNET.API
         public Task<string> GetNameAsync() => BridgeConnector.OnResult<string>("appGetName", "appGetNameCompleted");
 
 
-        internal App() 
+        private App() 
         {
-            CommandLine = new CommandLine();
+            CommandLine = CommandLine.Instance;
         }
 
         internal static App Instance

ElectronNET.API/CommandLine.cs

@@ -8,7 +8,7 @@ namespace ElectronNET.API
     /// </summary>
     public sealed class CommandLine
     {
-        internal CommandLine() { }
+        private CommandLine() { }
 
         internal static CommandLine Instance
         {

ElectronNET.API/Entities/TitleBarStyle.cs

@@ -28,4 +28,10 @@ namespace ElectronNET.API.Entities
         /// </summary>
         customButtonsOnHover
     }
+
+    public class TitleBarOverlayConfig
+    {
+        public string Color { get; set; }
+        public string SymbolColor { get; set; }
+    }
 }

ElectronNET.API/Entities/WebPreferences.cs

@@ -171,6 +171,12 @@ namespace ElectronNET.API.Entities
         /// </summary>
         public bool Offscreen { get; set; }
 
+        /// <summary>
+        /// Whether to enable built-in spellcheck
+        /// </summary>
+        [DefaultValue(true)]
+        public bool Spellcheck { get; set; } = true;
+
         /// <summary>
         /// Whether to run Electron APIs and the specified preload script in a separate
         /// JavaScript context. Defaults to false. The context that the preload script runs