Add deploy workflow

.github/workflows/deploy.yml

@@ -0,0 +1,27 @@
+name: Deploy
+
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup .NET
+        uses: actions/setup-dotnet@v4
+        with:
+          dotnet-version: 8.0.x
+
+      - name: Build
+        run: dotnet build SDL3-CS.sln -c Release
+
+      - name: Build Packages
+        run: dotnet pack SDL3-CS/SDL3-CS.csproj -c Release /p:Version=$(git describe --exact-match --tags HEAD)
+
+      - name: Publish tagged release to nuget.org
+        if: startsWith(github.ref, 'refs/tags/')
+        run: dotnet nuget push SDL3-CS/bin/Release/ppy.*.nupkg -s https://api.nuget.org/v3/index.json --api-key ${{secrets.NUGET_API_KEY}}