Support for parquet directories

[Florian R. Hölzlwimmer]

Hi, I just tried your tool and I find it super useful 👍
However, I noticed that one cannot simply cat whole directories:

# pqrs cat vcf.parquet 
Error: ParquetError(General("underlying IO error: Is a directory (os error 21)"))

However, this works:
pqrs cat vcf.parquet/**/*.parquet

It would be a nice convenience function if pqrs could handle this case.

[Manoj Karthick]

Thanks @Hoeze! I've added support for cat-ing parquet files recursively in directories with the latest release. Let me know if you face any issues.