hide tray icon (close #563)

Wox/MainWindow.xaml.cs

@@ -85,6 +85,13 @@ namespace Wox
                     }
                 }
             };
+            _settings.PropertyChanged += (o, e) =>
+            {
+                if (e.PropertyName == nameof(Settings.HideNotifyIcon))
+                {
+                    _notifyIcon.Visible = !_settings.HideNotifyIcon;
+                }
+            };
             InitializePosition();
         }
 
@@ -102,7 +109,7 @@ namespace Wox
             {
                 Text = Infrastructure.Constant.Wox,
                 Icon = Properties.Resources.app,
-                Visible = true
+                Visible = !_settings.HideNotifyIcon
             };
             var menu = new ContextMenuStrip();
             var items = menu.Items;