Move choosenim under Nim org

[juancarlospaco]

This idea is simple, move choosenim thats a very relevant tool to install the language and manage Nim versions
under the Nim organization on Github, to keep it under the Nim umbrella, and improve its visibility as a core tool.

[dom96]

Personally I would prefer to keep it where it is for now.

[shirleyquirk]

Nim is really heavily dependent upon it, for example if one wants nim doc to work. nim-lang/Nim#14424 https://forum.nim-lang.org/t/7702

While I'd prefer that Nim were better supported by os-specific packages, and maybe that's a better way to support Nim in the wild, choosenim is just so darn useful, i can't imagine Nim without its rustup. It's consistently the recommended method of installation, and when it doesn't work, it has such a disproportionate impact!

A broad ecosystem is as beneficial as a tightknit toolchain, and nothing prevents anyone from contributing on /dom96/choosenim vs /nim-lang/choosenim, so this isn't an attempt to change @dom96's mind, more of a love letter to the tool.

[dom96]

The way I see it is that this would be largely symbolic. I would prefer to see real action and that starts with Nimble: it's already in the nim-lang org but doesn't see much maintenance/development from the core Nim team. Let's change that first before doing anything with choosenim.

[juancarlospaco]

No correlation.