Update build.yml (#20)

.github/workflows/build.yml

@@ -5,6 +5,18 @@ on:
     branches: [ master ]
   pull_request:
     branches: [ master ]
+  release:
+    types:
+      - published
+
+env:
+  DOTNET_SKIP_FIRST_TIME_EXPERIENCE: 1
+  DOTNET_NOLOGO: true
+  NuGetDirectory: ${{ github.workspace}}/nuget
+
+defaults:
+  run:
+    shell: pwsh
 
 jobs:
   build:
@@ -26,3 +38,23 @@ jobs:
       run: dotnet build --no-restore /warnaserror
     - name: Test
       run: dotnet test --no-build --verbosity normal
+
+  publish_nuget:
+    if: github.event_name == 'release'
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Setup .NET
+        uses: actions/setup-dotnet@v1
+        with:
+          dotnet-version: 6.0.x
+
+      - run: dotnet pack --configuration Release --output ${{ env.NuGetDirectory }}
+
+      - uses: actions/upload-artifact@v3
+        with:
+          name: nuget
+          if-no-files-found: error
+          retention-days: 7
+          path: ${{ env.NuGetDirectory }}/*.nupkg
+