add validation for empty token and domain

go.mod

@@ -1,6 +1,6 @@
 module go.balki.me/cloudflare-dns-cli
 
-go 1.20
+go 1.21
 
 require (
 	github.com/libdns/cloudflare v0.1.0

main.go

@@ -113,6 +113,16 @@ func main() {
 	flag.BoolVar(&mx, "m", mx, "Set mx record with cname value")
 	flag.Parse()
 
+	if token == "" {
+		flag.Usage()
+		log.Panicln("empty cloudflare api token")
+	}
+
+	if domain == "" {
+		flag.Usage()
+		log.Panicln("empty domain name")
+	}
+
 	provider := cloudflare.Provider{APIToken: token}
 	zone := domain + "."