fix: 🐛 update README and Docker setup documentation for GitHub Container Registry support

.github/workflows/docker-image.yml

@@ -30,13 +30,24 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
       
-      - name: Extract metadata
-        id: meta
+      - name: Extract metadata for GHCR
+        id: meta-ghcr
         uses: docker/metadata-action@v5
         with:
-          images: |
-            ${{ env.REGISTRY_DOCKERHUB }}/${{ env.IMAGE_NAME }}
-            ${{ env.REGISTRY_GHCR }}/${{ env.IMAGE_NAME }}
+          images: ${{ env.REGISTRY_GHCR }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=ref,event=branch
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=raw,value=latest,enable={{is_default_branch}}
+      
+      - name: Extract metadata for Docker Hub
+        id: meta-dockerhub
+        if: secrets.DOCKERHUB_USERNAME != ''
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY_DOCKERHUB }}/${{ env.IMAGE_NAME }}
           tags: |
             type=ref,event=branch
             type=semver,pattern={{version}}
@@ -45,7 +56,7 @@ jobs:
             type=raw,value=latest,enable={{is_default_branch}}
       
       - name: Login to Docker Hub
-        if: github.event_name != 'pull_request'
+        if: github.event_name != 'pull_request' && secrets.DOCKERHUB_USERNAME != ''
         uses: docker/login-action@v3
         with:
           registry: ${{ env.REGISTRY_DOCKERHUB }}
@@ -60,13 +71,24 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
       
-      - name: Build and push
+      - name: Build and push to GHCR
         uses: docker/build-push-action@v5
         with:
           context: .
           platforms: linux/amd64,linux/arm64
           push: ${{ github.event_name != 'pull_request' }}
-          tags: ${{ steps.meta.outputs.tags }}
-          labels: ${{ steps.meta.outputs.labels }}
+          tags: ${{ steps.meta-ghcr.outputs.tags }}
+          labels: ${{ steps.meta-ghcr.outputs.labels }}
           cache-from: type=gha
           cache-to: type=gha,mode=max
+      
+      - name: Build and push to Docker Hub
+        if: github.event_name != 'pull_request' && secrets.DOCKERHUB_USERNAME != ''
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: ${{ steps.meta-dockerhub.outputs.tags }}
+          labels: ${{ steps.meta-dockerhub.outputs.labels }}
+          cache-from: type=gha