Go implementation of Apache Arrow

I admire people who go through libraries and re-implement them, especially because I found Arrow (and Parquet) code very annoying to understand.

The documentation doesn't cover the design decisions that the crew took, and what the concepts are in-depth.

At least Arrow improves upon Parquet, by actually adding a type for INT_8 and INT_16, which for some reason Parquet actually stores as (a less efficient column of) INT_32s.