Added desktop solution filter.

Loads on the projects required to run on desktop platforms.

Avalonia.Desktop.slnf

@@ -0,0 +1,60 @@
+{
+  "solution": {
+    "path": "Avalonia.sln",
+    "projects": [
+      "packages\\Avalonia\\Avalonia.csproj",
+      "samples\\ControlCatalog.NetCore\\ControlCatalog.NetCore.csproj",
+      "samples\\ControlCatalog\\ControlCatalog.csproj",
+      "samples\\IntegrationTestApp\\IntegrationTestApp.csproj",
+      "samples\\MiniMvvm\\MiniMvvm.csproj",
+      "samples\\SampleControls\\ControlSamples.csproj",
+      "samples\\Sandbox\\Sandbox.csproj",
+      "src\\Avalonia.Base\\Avalonia.Base.csproj",
+      "src\\Avalonia.Build.Tasks\\Avalonia.Build.Tasks.csproj",
+      "src\\Avalonia.Controls.ColorPicker\\Avalonia.Controls.ColorPicker.csproj",
+      "src\\Avalonia.Controls.DataGrid\\Avalonia.Controls.DataGrid.csproj",
+      "src\\Avalonia.Controls\\Avalonia.Controls.csproj",
+      "src\\Avalonia.DesignerSupport\\Avalonia.DesignerSupport.csproj",
+      "src\\Avalonia.Desktop\\Avalonia.Desktop.csproj",
+      "src\\Avalonia.Diagnostics\\Avalonia.Diagnostics.csproj",
+      "src\\Avalonia.Dialogs\\Avalonia.Dialogs.csproj",
+      "src\\Avalonia.FreeDesktop\\Avalonia.FreeDesktop.csproj",
+      "src\\Avalonia.Headless.Vnc\\Avalonia.Headless.Vnc.csproj",
+      "src\\Avalonia.Headless\\Avalonia.Headless.csproj",
+      "src\\Avalonia.MicroCom\\Avalonia.MicroCom.csproj",
+      "src\\Avalonia.Native\\Avalonia.Native.csproj",
+      "src\\Avalonia.OpenGL\\Avalonia.OpenGL.csproj",
+      "src\\Avalonia.ReactiveUI\\Avalonia.ReactiveUI.csproj",
+      "src\\Avalonia.Remote.Protocol\\Avalonia.Remote.Protocol.csproj",
+      "src\\Avalonia.Themes.Fluent\\Avalonia.Themes.Fluent.csproj",
+      "src\\Avalonia.Themes.Simple\\Avalonia.Themes.Simple.csproj",
+      "src\\Avalonia.X11\\Avalonia.X11.csproj",
+      "src\\Linux\\Avalonia.LinuxFramebuffer\\Avalonia.LinuxFramebuffer.csproj",
+      "src\\Markup\\Avalonia.Markup.Xaml.Loader\\Avalonia.Markup.Xaml.Loader.csproj",
+      "src\\Markup\\Avalonia.Markup.Xaml\\Avalonia.Markup.Xaml.csproj",
+      "src\\Markup\\Avalonia.Markup\\Avalonia.Markup.csproj",
+      "src\\Skia\\Avalonia.Skia\\Avalonia.Skia.csproj",
+      "src\\Windows\\Avalonia.Direct2D1\\Avalonia.Direct2D1.csproj",
+      "src\\Windows\\Avalonia.Win32.Interop\\Avalonia.Win32.Interop.csproj",
+      "src\\Windows\\Avalonia.Win32\\Avalonia.Win32.csproj",
+      "src\\tools\\DevAnalyzers\\DevAnalyzers.csproj",
+      "src\\tools\\DevGenerators\\DevGenerators.csproj",
+      "tests\\Avalonia.Base.UnitTests\\Avalonia.Base.UnitTests.csproj",
+      "tests\\Avalonia.Benchmarks\\Avalonia.Benchmarks.csproj",
+      "tests\\Avalonia.Controls.DataGrid.UnitTests\\Avalonia.Controls.DataGrid.UnitTests.csproj",
+      "tests\\Avalonia.Controls.UnitTests\\Avalonia.Controls.UnitTests.csproj",
+      "tests\\Avalonia.DesignerSupport.TestApp\\Avalonia.DesignerSupport.TestApp.csproj",
+      "tests\\Avalonia.DesignerSupport.Tests\\Avalonia.DesignerSupport.Tests.csproj",
+      "tests\\Avalonia.Direct2D1.RenderTests\\Avalonia.Direct2D1.RenderTests.csproj",
+      "tests\\Avalonia.Direct2D1.UnitTests\\Avalonia.Direct2D1.UnitTests.csproj",
+      "tests\\Avalonia.IntegrationTests.Appium\\Avalonia.IntegrationTests.Appium.csproj",
+      "tests\\Avalonia.LeakTests\\Avalonia.LeakTests.csproj",
+      "tests\\Avalonia.Markup.UnitTests\\Avalonia.Markup.UnitTests.csproj",
+      "tests\\Avalonia.Markup.Xaml.UnitTests\\Avalonia.Markup.Xaml.UnitTests.csproj",
+      "tests\\Avalonia.ReactiveUI.UnitTests\\Avalonia.ReactiveUI.UnitTests.csproj",
+      "tests\\Avalonia.Skia.RenderTests\\Avalonia.Skia.RenderTests.csproj",
+      "tests\\Avalonia.Skia.UnitTests\\Avalonia.Skia.UnitTests.csproj",
+      "tests\\Avalonia.UnitTests\\Avalonia.UnitTests.csproj"
+    ]
+  }
+}