Added workflow to create docker image

.github/workflows/create-docker-image-on-release.yml

@@ -0,0 +1,39 @@
+name: Publish Docker Image to GHCR
+
+on:
+  release:
+    types:
+      - published
+  workflow_dispatch:
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}/artsdata-rdf-fetcher
+
+jobs:
+  build-and-publish:
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v3
+
+    - name: Log in to GHCR
+      uses: docker/login-action@v3
+      with:
+        registry: ${{ env.REGISTRY }}
+        username: ${{ github.actor }}
+        password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Extract metadata (tags, labels) for Docker
+      id: meta
+      uses: docker/metadata-action@v5
+      with:
+        images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+
+    - name: Build and push Docker image
+      uses: docker/build-push-action@v6
+      with:
+        push: true
+        tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}