add workflow to publish nuget package

Author: atwayne

.github/workflows/nuget-publish.yml

@@ -0,0 +1,37 @@
+name: nuget publish
+
+on: 
+  release:
+    types: # This configuration does not affect the page_build event above
+      - created
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: GitHub Environment Variables Action
+      uses: FranzDiebold/github-env-vars-action@v2
+
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v1
+      with:
+        dotnet-version: 5.0.x
+
+    - name: dotnet restore
+      run: dotnet restore
+
+    - name: dotnet build
+      run: dotnet build --no-restore -c Release
+
+    - name: dotnet test
+      run: dotnet test --no-build -c Release
+
+    - name: dotnet pack
+      run: dotnet pack --no-build -c Release --include-source --include-symbols -p:PackageVersion='${{ env.CI_REF_NAME }}' -p:SymbolPackageFormat=snupkg
+      
+    - name: dotnet nuget push
+      run: dotnet nuget push **/*.nupkg --api-key ${{secrets.NUGET_ORG_API_KEY}} --source https://api.nuget.org/v3/index.json