Add support for other formats like [HJSON](http://hjson.org/), [TOML](https://github.com/toml-lang/toml), [MessagePack](https://msgpack.org/), [CSV](http://php.net/manual/en/function.fgetcsv.php)... Maybe also add support for other formats from [Comparison of data serialization formats](https://en.wikipedia.org/wiki/Comparison_of_data_serialization_formats). Also, add support for loading and writing config to environment variables and [.env](https://github.com/vlucas/phpdotenv).