publish to GHCR as well

.github/SECRETS.md

@@ -3,3 +3,4 @@
 * `GH_PAT` - A GitHub [Personal Access Token](https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/creating-a-personal-access-token) with `repo` permissions.
 * `DOCKER_USERNAME` - Your Docker Hub username.
 * `DOCKER_PASSWORD` - Your Docker Hub password/access token.
+* `GH_USERNAME` - Your GitHub username.

.github/workflows/build.yml

@@ -8,6 +8,7 @@ on:
 env:
   DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
   DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
+  GH_USERNAME: ${{ secrets.GH_USERNAME }}
 
 jobs:
   build:
@@ -27,3 +28,11 @@ jobs:
           password: ${{ secrets.DOCKER_PASSWORD }}
       - name: Push the Docker Image
         run: docker push "$DOCKER_USERNAME"/lidarr-true-singles:latest
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ secrets.GH_USERNAME }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Push the Docker Image to GitHub Container Registry
+        run: docker push ghcr.io/"$GH_USERNAME"/lidarr-true-singles:latest