write config file in indented JSON

EliteBGS/Util/Config.cs

@@ -36,6 +36,7 @@ namespace EliteBGS.Util {
                 filestream.Flush();
                 using (StreamWriter file = new StreamWriter(filestream, Encoding.UTF8)) {
                     var stream = new JsonTextWriter(file);
+                    stream.Formatting = Formatting.Indented;
                     serializer.Serialize(stream, global_config);
                 }
             }