See the website at https://euvatrates.com for all information about this project.
You can simply request https://euvatrates.com/rates.json to load the data, or you can self-host the information by cloning the repository. The project is also on Bower if that's your thing: bower install euvatrates.com
Simply send a pull request! For changes to rates.json include the source for the change in the commit message, and also add it to the Data Sources list in index.html if it's a new resource.
If you're not sure if a different pull request is in line with my idea about the project, please open an issue for discussion.