Endianness

[Michael-K-GH]

Implement a keyword to support specifying the endianness of the data.
Endianness should be specified at the beginning of the schema file, before anything else (including include statements).
Proposed syntax introduces the order keyword:

order little-endian;

[AridTag]

I just stumbled upon this repo from an old reddit thread.

When this feature gets worked on it might be nice to be able to override endianness on a per field basis. One of the data formats I'm dealing with right now likes to switch up the endianness of fields as an obfuscation tactic. It even uses non standard byte orderings for a few of the fields.