Fix Docker workflow

Author: PassiveLemon

.github/workflows/docker.yml

@@ -32,6 +32,7 @@ jobs:
       - name: Setup building file structure
         run: |
           cp -lr $GITHUB_WORKSPACE/src/ $GITHUB_WORKSPACE/docker/
+          cp -lr $GITHUB_WORKSPACE/example/ $GITHUB_WORKSPACE/docker/
 
       - name: Build and push Docker image
         uses: docker/build-push-action@v6