Add GHCR Docker image mirror

Author: gabe565

.github/workflows/dockerhub.yml

@@ -27,6 +27,13 @@ jobs:
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
+      -
+        name: Login to GHCR
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ github.token }}
       - 
         name: Set tag name
         run: |
@@ -40,5 +47,7 @@ jobs:
         uses: docker/build-push-action@v3
         with:
           push: true
-          tags: b4bz/homer:${{env.IMAGE_TAG}}
-          platforms: linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64
+          tags: |
+            b4bz/homer:${{env.IMAGE_TAG}}
+            ghcr.io/${{ github.repository }}:${{ env.IMAGE_TAG }}
+          platforms: linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64