If you want to include a config with your asset, you can do so by putting the RTT-Definition.xml file inside your asset's or mod's folder, the same as with Vehicle Effects. These are loaded after the default and before the user configuration, so you override the mod's defaults but users can override your included config.

You can use the in-game editor to create your config. The in-game editor edits %localappdata%\Colossal Order\Cities_Skylines\RTT-Definition.xml, so you can use it to create your config.

1. Make a backup of the config file.
   
2. Delete or empty the config file.
   
3. UPLOAD AND SUBSCRIBE TO YOUR ASSET! This is important, make sure that you create the config for the WORKSHOP version of your asset(s) since uploading changes the asset name. A config for your local version won't be applied to the workshop version!
   
4. Create the config for your workshop version using the in-game editor.
   
5. Save the config and update your workshop item to include it.