Language code script subtags are incorrectly capitalized

[wavebeem]

According to RFC 5646, script tags within language codes (e.g. the Hans in zh-Hans) should start with a capital letter

They used to start with a capital letter in PokeAPI, but at some point they changed to be lowercased like zh-hans.

This unexpected change caused visual regressions in PKMN.help because my application is using exact string lookup in a translation table right now.

(Edit: I realize now that case-sensitive lookup is a spec violation. This is my fault, but it would still be nice to have the canonical capitalization in PokeAPI)

How to reproduce

1. https://pokeapi.co/api/v2/pokemon-species/37/
2. Look under names
3. See the code zh-hans used instead of zh-Hans