Add comments about OSX,Linux, Windows platform options

src/Avalonia.Native/AvaloniaNativePlatformExtensions.cs

@@ -26,19 +26,52 @@ public static T UseAvaloniaNative<T>(this T builder)
         }
     }
 
+    /// <summary>
+    /// OSX backend options.
+    /// </summary>
     public class AvaloniaNativePlatformOptions
     {
+        /// <summary>
+        /// Deferred renderer would be used when set to true. Immediate renderer when set to false. The default value is true.
+        /// </summary>
+        /// <remarks>
+        /// Avalonia has two rendering modes: Immediate and Deferred rendering.
+        /// Immediate re-renders the whole scene when some element is changed on the scene. Deferred re-renders only changed elements.
+        /// </remarks>
         public bool UseDeferredRendering { get; set; } = true;
+
+        /// <summary>
+        /// Determines whether to use GPU for rendering in your project. The default value is true.
+        /// </summary>
         public bool UseGpu { get; set; } = true;
+
+        /// <summary>
+        /// Embeds popups to the window when set to true. The default value is false.
+        /// </summary>
         public bool OverlayPopups { get; set; }
+
+        /// <summary>
+        /// This property should be used in case you want to build Avalonia OSX native part by yourself
+        /// and make your Avalonia app run with it. The default value is null.
+        /// </summary>
         public string AvaloniaNativeLibraryPath { get; set; }
     }
 
     // ReSharper disable once InconsistentNaming
+    /// <summary>
+    /// OSX front-end options.
+    /// </summary>
     public class MacOSPlatformOptions
     {
+        /// <summary>
+        /// Determines whether to show your application in the dock when it runs. The default value is true.
+        /// </summary>
         public bool ShowInDock { get; set; } = true;
-
+
+        /// <summary>
+        /// By default, Avalonia adds items like Quit, Hide to the OSX Application Menu.
+        /// You can prevent Avalonia from adding those items to the OSX Application Menu with this property. The default value is false.
+        /// </summary>
         public bool DisableDefaultApplicationMenuItems { get; set; }
     }
 }

src/Avalonia.X11/X11Platform.cs

@@ -162,14 +162,49 @@ bool ShouldUseXim()
 
 namespace Avalonia
 {
-
+    /// <summary>
+    /// Platform-specific options which apply to Linux.
+    /// </summary>
     public class X11PlatformOptions
     {
+        /// <summary>
+        /// Enables native Linux EGL when set to true. The default value is false.
+        /// </summary>
         public bool UseEGL { get; set; }
+
+        /// <summary>
+        /// Determines whether to use GPU for rendering in your project. The default value is true.
+        /// </summary>
         public bool UseGpu { get; set; } = true;
+
+        /// <summary>
+        /// Embeds popups to the window when set to true. The default value is false.
+        /// </summary>
         public bool OverlayPopups { get; set; }
+
+        /// <summary>
+        /// Enables global menu support on Linux desktop environments where it's supported (e. g. XFCE and MATE with plugin, KDE, etc).
+        /// The default value is false.
+        /// </summary>
         public bool UseDBusMenu { get; set; }
+
+        /// <summary>
+        /// Deferred renderer would be used when set to true. Immediate renderer when set to false. The default value is true.
+        /// </summary>
+        /// <remarks>
+        /// Avalonia has two rendering modes: Immediate and Deferred rendering.
+        /// Immediate re-renders the whole scene when some element is changed on the scene. Deferred re-renders only changed elements.
+        /// </remarks>
         public bool UseDeferredRendering { get; set; } = true;
+
+        /// <summary>
+        /// Determines whether to use IME.
+        /// IME would be enabled by default if the current user input language is one of the following: Mandarin, Japanese, Vietnamese or Korean.
+        /// </summary>
+        /// <remarks>
+        /// Input method editor is a component that enables users to generate characters not natively available 
+        /// on their input devices by using sequences of characters or mouse operations that are natively available on their input devices.
+        /// </remarks>
         public bool? EnableIme { get; set; }
 
         public IList<GlVersion> GlProfiles { get; set; } = new List<GlVersion>
@@ -190,6 +225,13 @@ public class X11PlatformOptions
             "llvmpipe"
         };
         public string WmClass { get; set; } = Assembly.GetEntryAssembly()?.GetName()?.Name ?? "AvaloniaApplication";
+
+        /// <summary>
+        /// Enables multitouch support. The default value is true.
+        /// </summary>
+        /// <remarks>
+        /// Multitouch allows a surface (a touchpad or touchscreen) to recognize the presence of more than one point of contact with the surface at the same time.
+        /// </remarks>
         public bool? EnableMultiTouch { get; set; } = true;
     }
     public static class AvaloniaX11PlatformExtensions

src/Windows/Avalonia.Win32/Win32Platform.cs

@@ -35,15 +35,46 @@ public static T UseWin32<T>(
         }
     }
 
+    /// <summary>
+    /// Platform-specific options which apply to Windows.
+    /// </summary>
     public class Win32PlatformOptions
     {
+        /// <summary>
+        /// Deferred renderer would be used when set to true. Immediate renderer when set to false. The default value is true.
+        /// </summary>
+        /// <remarks>
+        /// Avalonia has two rendering modes: Immediate and Deferred rendering.
+        /// Immediate re-renders the whole scene when some element is changed on the scene. Deferred re-renders only changed elements.
+        /// </remarks>
         public bool UseDeferredRendering { get; set; } = true;
-
+
+        /// <summary>
+        /// Enables ANGLE for Windows. For every Windows version that is above Windows 7, the default is true otherwise it's false.
+        /// </summary>
+        /// <remarks>
+        /// GPU rendering will not be enabled if this is set to false.
+        /// </remarks>
         public bool? AllowEglInitialization { get; set; }
 
+        /// <summary>
+        /// Enables multitouch support. The default value is true.
+        /// </summary>
+        /// <remarks>
+        /// Multitouch allows a surface (a touchpad or touchscreen) to recognize the presence of more than one point of contact with the surface at the same time.
+        /// </remarks>
         public bool? EnableMultitouch { get; set; } = true;
+
+        /// <summary>
+        /// Embeds popups to the window when set to true. The default value is false.
+        /// </summary>
         public bool OverlayPopups { get; set; }
+
+        /// <summary>
+        /// Avalonia would try to use native Widows OpenGL when set to true. The default value is false.
+        /// </summary>
         public bool UseWgl { get; set; }
+
         public IList<GlVersion> WglProfiles { get; set; } = new List<GlVersion>
         {
             new GlVersion(GlProfileType.OpenGL, 4, 0),