add section Nix Interpreters

[milahu]

No description provided.

[cyntheticfox]

Both of the added projects look promising, but neither look mature enough atm to be actively used yet, with the JS implementation being too new. If development on them continues and they're increasingly adopted, I'd be comfortable adding them later on.

[milahu]

to continue ...

added "status" = how much of "the perfect nix" is implemented

Nix Interpreters

aka: Nix Evaluators

• nix - the original nix interpreter in C++. aka nix.cc. Status: 90%
• tour of nix - nix interpreter in javascript. aka nix.js.
  the original nix interpreter, compiled to asm.js. Status: nix-instantiate
• hnix - nix interpreter in haskell. aka nix.hs. Status: 50%
• rnix-lsp - nix interpreter in rust. error-tolerant interpreter for intellisense. based on the rnix-parser. aka nix.rs. Status: 20%
• Toros - Nix implementation in Rust. Based on the NixEL parser. aka nix.rs. Status: 10%
• nix-eval-js - Nix interpreter in pure JavaScript. Proof of concept. Based on the lezer-parser-nix parser. aka nix.js. Status: 5%

in a distant future, nickel can interpret nix tweag/nickel#93