feat(draw): make output file is optional

cmd/asciigen/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"fmt"
 	"log"
 	"os"
 )
@@ -17,11 +18,6 @@ func main() {
 		log.Fatalln("ENV QMK_KEYMAP empty")
 	}
 
-	filenameOut := os.Getenv("OUT")
-	if filenameOut == "" {
-		log.Fatalln("ENV OUT empty")
-	}
-
 	bytesInfo, err := os.ReadFile(filenameInfo)
 	if err != nil {
 		log.Fatalln("Failed to read file", filenameInfo, err)
@@ -46,8 +42,13 @@ func main() {
 		qmkInfo.Layouts,
 		qmkKeymap,
 	)
+	fmt.Println(result)
 
-	if err := os.WriteFile(filenameOut, []byte(result), 0o644); err != nil {
-		log.Fatalln("Failed to write file", filenameOut, err)
+    // Optional
+	filenameOut := os.Getenv("OUT")
+	if filenameOut != "" {
+		if err := os.WriteFile(filenameOut, []byte(result), 0o644); err != nil {
+			log.Fatalln("Failed to write file", filenameOut, err)
+		}
 	}
 }