Add force-rebuild flag to allow user to rebuild docker container explicitly.
diff --git a/dockerimg/dockerimg.go b/dockerimg/dockerimg.go
index 976a979..3903f48 100644
--- a/dockerimg/dockerimg.go
+++ b/dockerimg/dockerimg.go
@@ -654,7 +654,7 @@
 	cmd.Dir = gitRoot
 	cmd.Stdout = stdout
 	cmd.Stderr = stderr
-	fmt.Printf("building docker image %s... (use -verbose to see build output)\n", imgName)
+	fmt.Printf("🏗️ building docker image %s... (use -verbose to see build output)\n", imgName)
 	dockerfileContent, err := os.ReadFile(dockerfilePath)
 	if err != nil {
 		return "", fmt.Errorf("failed to read Dockerfile: %w", err)