some refactoring

server/Configure.go

@@ -0,0 +1,12 @@
+package server
+
+import (
+	"dns_service/api"
+	"net/http"
+)
+
+func Configure() {
+	http.Handle("/", api.SpaHandler(http.FS(api.Frontend)))
+	http.HandleFunc("/api/settings", api.Settings)
+	http.HandleFunc("/api/settings/file", api.SettingsFile)
+}