Add solution filter for VS projects (NuGet#4672)

NuGet-VS.slnf

@@ -0,0 +1,23 @@
+{
+  "solution": {
+    "path": "NuGet.sln",
+    "projects": [
+      "src\\NuGet.Clients\\NuGet.Console\\NuGet.Console.csproj",
+      "src\\NuGet.Clients\\NuGet.Indexing\\NuGet.Indexing.csproj",
+      "src\\NuGet.Clients\\NuGet.PackageManagement.PowerShellCmdlets\\NuGet.PackageManagement.PowerShellCmdlets.csproj",
+      "src\\NuGet.Clients\\NuGet.PackageManagement.UI\\NuGet.PackageManagement.UI.csproj",
+      "src\\NuGet.Clients\\NuGet.PackageManagement.VisualStudio\\NuGet.PackageManagement.VisualStudio.csproj",
+      "src\\NuGet.Clients\\NuGet.SolutionRestoreManager\\NuGet.SolutionRestoreManager.csproj",
+      "src\\NuGet.Clients\\NuGet.Tools\\NuGet.Tools.csproj",
+      "src\\NuGet.Clients\\NuGet.VisualStudio\\NuGet.VisualStudio.csproj",
+      "src\\NuGet.Clients\\NuGet.VisualStudio.Client\\NuGet.VisualStudio.Client.csproj",
+      "src\\NuGet.Clients\\NuGet.VisualStudio.Common\\NuGet.VisualStudio.Common.csproj",
+      "src\\NuGet.Clients\\NuGet.VisualStudio.Contracts\\NuGet.VisualStudio.Contracts.csproj",
+      "src\\NuGet.Clients\\NuGet.VisualStudio.Implementation\\NuGet.VisualStudio.Implementation.csproj",
+      "src\\NuGet.Clients\\NuGet.VisualStudio.Internal.Contracts\\NuGet.VisualStudio.Internal.Contracts.csproj",
+      "src\\NuGet.Clients\\NuGet.VisualStudio.Interop\\NuGet.VisualStudio.Interop.csproj",
+      "src\\NuGet.Clients\\NuGet.VisualStudio.OnlineEnvironment.Client\\NuGet.VisualStudio.OnlineEnvironment.Client.csproj",
+      "src\\NuGet.Clients\\NuGetConsole.Host.PowerShell\\NuGetConsole.Host.PowerShell.csproj",
+    ]
+  }
+}

docs/workflow.md

@@ -58,7 +58,7 @@ The recommended pattern for release branches is slightly different. We should pr
 ### Solution and project folder structure and naming
 
 The NuGet.Client repo currently has only one solution file named `NuGet.sln`. We do not want/need to have more than one solution file.
-If deemed necessary by the team, we can consider solution filters at a future point.
+We have some Solution Filters (.slnf files), currently for projects specific to working with NuGet's Command line, VS, or UnitTests directly, and can consider more based on team and community feedback.
 
 - Every project in the NuGet.Client repo should be [PackageReference-based](https://docs.microsoft.com/en-us/nuget/consume-packages/package-references-in-project-files) based and if possible (read this as not .NET Framework WPF), an [SDK-based](https://docs.microsoft.com/en-us/visualstudio/msbuild/how-to-use-project-sdk) one.
 - The production source code is under the `src` folder.