Add example for use with JuliaDB

[schlichtanders]

Thanks for this support for Parquet files!

Reading through JuliaDB and seeing that it only supports CSV files so far, I searched for a tutorial about how to make it read Parquet files, but was not successful.

Maybe it isn't even possible? In any case it would be great to have a little note about it. In best case, even with example about how to do it.