feat: nixvim refactor

modules/home-manager/programs/nixvim/presets/languages/rust.nix

@@ -0,0 +1,20 @@
+{ lib, config, ... }:
+let
+  cfg = config.presets.languages.rust;
+in
+{
+  options.presets.languages.rust = {
+    enable = lib.mkEnableOption "Rust";
+  };
+
+  config = lib.mkIf cfg.enable {
+    plugins = {
+      conform-nvim.formattersByFt.rust = [ "rustfmt" ];
+      lsp.servers.rust-analyzer = {
+        enable = true;
+        installCargo = false;
+        installRustc = false;
+      };
+    };
+  };
+}