ISO country code for national teams ?

Done, and thank you — the "Türkiye vs Turkey" example is exactly why this needed doing. Every team now carries `country_code` next to `country`: {"id": 932, "name": "Türkiye", "country": "Türkiye", "country_code": "TR"} 321 of 328 national teams have it, and 6,384 teams in total. It cost us nothing to collect: the code was already arriving in every match payload and we simply were not keeping it. Two things it is not, and I would rather say them here than have you find out: 1. It is not strictly ISO 3166-1, and I am not going to label it as such. It agrees with ISO wherever ISO has a code, and uses the customary one where it does not — England EN, Scotland SX, Wales WA, Northern Ireland NX, all four of which are GB in ISO. If you need real ISO for those four, map them yourself; at least now you have something stable to map from. 2. It identifies the country, not the team. Argentina and Argentina U23 both carry AR. Keep using id to identify a team. Empty string when we have none — a handful of historical sides (USSR, Yugoslavia, East Germany) have no code to give, and 1,856 clubs have never appeared in a fixture carrying country data. Docs: /docs/football/teams-players/ under "Matching a team to a country". - Bzzoiro