GitHub Workflow added

.github/workflows/docker-publish.yml

@@ -0,0 +1,35 @@
+name: Build and Publish Docker image
+
+on:
+  push:
+    branches: [ "main" ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          push: true
+          tags: |
+            ghcr.io/${{ github.repository_owner }}/opencloud-oidc-webfinger-proxy:latest
+            ghcr.io/${{ github.repository_owner }}/opencloud-oidc-webfinger-proxy:${{ github.sha }}
+          platforms: linux/amd64,linux/arm64