Add NuGet badge and organize GitHub workflows

- Added a NuGet badge to README.md for KlutzyNinja.VisualStudioInterop.
- Created a new folder structure in vsinterop.slnx for GitHub workflows.
- Added dotnet.yml and publish.yml workflow files.

Author: JeremyKuhne

README.md

@@ -1,5 +1,6 @@
 # Visual Studio Interop
 
 [![Build](https://github.com/JeremyKuhne/vsinterop/actions/workflows/dotnet.yml/badge.svg)](https://github.com/JeremyKuhne/vsinterop/actions/workflows/dotnet.yml)
+[![NuGet](https://img.shields.io/nuget/v/KlutzyNinja.VisualStudioInterop.svg)](https://www.nuget.org/packages/KlutzyNinja.VisualStudioInterop/)
 
 Provides fast, direct access to Visual Studio COM interfaces on both .NET Framework and .NET.

vsinterop.slnx

@@ -11,6 +11,10 @@
     <File Path="README.md" />
     <File Path="THIRD-PARTY-NOTICES.TXT" />
   </Folder>
+  <Folder Name="/Solution Items/GitHub/">
+    <File Path=".github/workflows/dotnet.yml" />
+    <File Path=".github/workflows/publish.yml" />
+  </Folder>
   <Project Path="vsinterop.tests/vsinterop.tests.csproj" Id="ac151218-63ff-4b07-a187-e60cea0c4ee1">
     <Platform Project="x64" />
   </Project>