fix(core): update

ts/index.ts

@@ -11,9 +11,11 @@ export class SmartXml {
   public createXmlFromObject(jsObject: any): string {
     const jsToXmlParser = new plugins.fastXmlParser.j2xParser({
       ignoreAttributes: false,
-      attributeNamePrefix: "@_"
+      attributeNamePrefix: "@_",
+      format: true,
+      indentBy: '  ',
     });
     const xml = jsToXmlParser.parse(jsObject);
-    return xml;
+    return '<?xml version="1.0" encoding="UTF-8"?>\n' + xml;
   }
 }